Jennifer Lentz — Psychoacoustics- Perception of Normal and Impaired Hearing with Audiology Applications

688 published claims from this book.

• ‘Sound level’ is a deliberately vague unit-free term for sound size
• 95 percent of auditory nerve fibers carry coded signals from inner hair cells upward
• A 1 dB SNR improvement boosts intelligibility by 7 to 19 percent
• A 1 dB SNR improvement raises speech intelligibility by 7 to 19 percent.
• A 1 Pa peak-amplitude tone produces 91 dB SPL
• A 10 dB increase always doubles perceived loudness above 40 dB
• A 5-dB hearing asymmetry doubles the perceived interaural level difference
• A filter’s transfer function describes gain in dB independent of sound level.
• A fixed ITD spans more cycles at high frequencies than low
• A full clinical audiogram can be collected in about fifteen minutes.
• A masker masks most when its frequency matches the signal frequency
• A masker only shifts thresholds that already lie below its EML.
• A masker’s intensity, frequency content, and temporal pattern determine its masking capability.
• A missing audiometric shadow curve reveals feigned (non-organic) hearing loss.
• A narrow noise band can mask signals multiple octaves away at high stimulus levels.
• A pure tone’s peak amplitude is the maximum pressure it achieves per cycle.
• A sound must decay enough before a following sound stops fusing with it
• A sound’s bandwidth independently affects how loud it sounds.
• A sound’s softness is only meaningful relative to who can hear it
• A tone and wideband noise of very different levels can equally sound loud
• A waveform’s sharpness dictates how many high-frequency sine waves it contains
• A widely used audiometric standard was calibrated roughly 10 dB off
• A worked dB EML example shows masking calculations in practice.
• A-weighted decibels better predict hearing damage than unweighted sound pressure level.
• A-weighted sound pressure level misrepresents the loudness of broadband noises
• ABLB laddergram rung divergence reveals whether loudness grows faster in an impaired ear
• Absence of loudness recruitment signals retrocochlear rather than cochlear pathology
• Absence of recruitment in sensorineural loss signals retrocochlear pathology.
• Absolute frequency discrimination worsens as reference frequency increases
• Absolute threshold is the minimum detectable sound level without external noise
• Acoustic head shadow creates a better ear with higher SNR in everyday listening
• Across-filter neural synchrony provides a robust pitch code
• Active outer hair cell processing boosts internal response levels by up to 40 dB
• Adaptive procedures converge on thresholds without explicit psychometric functions
• Adaptive staircases track a listener’s responses to set signal level
• Adaptive step size must be smaller than the psychometric function’s range
• Adding a matched noise to the opposite ear can lower masking.
• Adding correlated noise across ears can improve rather than worsen monaural detection
• All sound locations sharing one ITD form an infinite cone of confusion
• Alternate binaural loudness balancing plots recruitment as non-parallel laddergram rungs
• Amount of masking is expressed as a decibel difference, not an absolute SPL level
• Amplification cannot restore sound localization impaired by binaural encoding loss.
• Amplification only compensates for elevated thresholds, not other perceptual deficits from hearing loss.
• Amplitude modulation below about 60 Hz is well represented in hearing
• Amplitude-modulated noises alone can carry recognizable melodies.
• Amplitude-modulated sounds split into slow-varying envelope and fast-varying fine structure
• An 8 dB better-ear advantage can raise word identification by 56 percentage points
• An auditory spectrum maps cochlear excitation level against ERB-scaled frequency
• An unusually low false positive rate signals a patient exaggerating hearing loss
• Antiphasic speech improves word identification by 20 percentage points at low SNRs.
• ASHA prescribes 1-2 second steady and 200-ms pulsed tones for audiometry
• Asymmetrical-hearing-loss listeners must physically reposition to exploit their better ear
• At 1000 Hz humans detect frequency changes of about 0.2 percent
• Audibility deficits must be corrected before supra-threshold factors can be studied.
• Audibility thresholds can be expressed on physical or perceptual decibel scales
• Audiograms and frequency selectivity fail to predict pitch perception deficits
• Audiograms test pure-tone detection because pure tones are maximally frequency-specific
• Audiology is rooted in psychoacoustics and remains founded on it
• Audiometry pure-tone durations are set by perception, not acoustic independence
• Auditory assessment must account for the listener’s response bias, not just sensitivity
• Auditory frequency is encoded by both place and temporal codes.
• Auditory integration over time may involve intelligent selection of informative samples
• Auditory nerve fibers divide into three types by spontaneous firing rate.
• Auditory nerve fibers’ thresholds correlate inversely with their spontaneous firing rates.
• Auditory nerve phase locking can encode slow waveform fluctuations across filters
• Auditory nerve phase locking fails at high frequencies, leaving only the place code
• Auditory neuropathy impairs temporal gap detection while SNHL patients stay near normal.
• Auditory perception depends on understanding ear capabilities and hearing loss effects
• Auditory perception is a four-level hierarchy from detection to comprehension.
• Auditory processing disorder is a contested diagnosis lacking a single-locus definition
• Auditory processing disorder is diagnosed by ruling out peripheral and cognitive causes
• Auditory stimuli separate into fine structure and slower envelope
• Auditory tests present sounds in ascending steps from soft to uncomfortably loud
• Band-pass filters are specified by either two cutoffs or center frequency plus bandwidth
• Bandwidth-limiting devices degrade temporal coding even when speech remains intelligible
• Basilar membrane tuning is sharper in living than dead cochleae
• Basilar membrane vibration can be measured in vivo by tracking a bead’s movement
• Behavioral psychoacoustics tests detect retrocochlear pathology poorly but rule out healthy ears well
• Bell Labs pursued only hearing questions relevant to telephone engineering.
• Bell Labs research priorities were shaped by telephone engineering needs
• Beyond threshold, masker and signal levels rise one-for-one in decibels
• Binaural sound lateralizes to the ear receiving the louder signal
• Binaural summation gives a consistent two-ears vs one-ear benefit
• Binaural summation largely survives sensorineural hearing loss when sounds stay audible
• Both conductive and sensorineural damage drastically alters absolute threshold curves.
• Both liberal and conservative response criteria distort threshold estimates and lower percent correct
• Both place and temporal codes could underlie pitch, confounding identification of the main code
• Boundary curve slope in a psychometric function quantifies listener response certainty.
• Brief quiet gaps in sounds can introduce spectral cues that contaminate gap detection results
• Brief tones inject extra frequencies called spectral splatter into the stimulus
• Broad filters and lost suppression increase masking and blur spectral contrasts.
• Broadband maskers at low levels mask mid frequencies more than extremes.
• Broadband noise yields better intensity discrimination than pure tones by engaging multiple frequency regions
• Categorical loudness scaling measures uncomfortable and comfortable loudness levels using verbal categories
• Central auditory processing across frequencies produces the near miss
• Central auditory processing diagnosis requires exclusionary peripheral and cognitive tests
• Central auditory tests gain diagnostic value only by ruling out peripheral causes.
• Classical spectral-peak vowel coding is especially vulnerable to noise and level changes
• Clinical audiogram testing standardizes stimulus durations to exploit temporal integration
• Clinical audiology’s testing tools originated from psychoacoustic research
• Clinical LDL testing uses categorized loudness scaling with ascending stepped levels
• Clinical maskers must be wider than the critical band to work
• Clinical masking directly applies Fletcher’s critical band theory
• Clinical threshold changes are measured relative to normative curves, not in absolute dB SPL
• Clinical threshold testing uses undefined observation intervals to prevent anticipation from lowering thresholds.
• Cochlear damage increases susceptibility to masking, hurting speech in noise.
• Cochlear frequency selectivity decreases as sound level increases
• Combined outer and middle ear amplification spans roughly 600 to 4000 Hz
• Combining electric implant with residual acoustic hearing improves pitch perception
• Comparing hearing-impaired and normal listeners requires controlling for both sensation level and absolute level
• Complex sounds allow envelope time-difference coding at high frequencies
• Compression amplification partially restores distorted loudness perception in sensorineural hearing loss
• Compression hearing aids distort spectral temporal and binaural cues in poorly understood ways
• Conductive hearing loss can be modeled as a filter, but sensorineural loss cannot
• Conductive losses act as filters but sensorineural losses add distortions beyond attenuation.
• Constant-stimuli threshold measurement is time consuming because many trials are needed per level.
• Contralateral interference reveals true thresholds about 15-20 dB below the interference level
• Corporate and technical goals, notably telephony, shaped which auditory abilities researchers studied
• Critical bandwidth is measured through masking effects rather than direct perception
• Cross-hearing via bone conduction can contaminate thresholds, requiring masking in audiometry.
• Cross-modality scaling yields a true ratio scale that numeric rating cannot guarantee.
• Damage location in the ear maps onto specific frequency regions of hearing loss.
• Damage to high-threshold auditory nerve fibers can escape threshold detection yet impair speech-in-noise perception.
• Damage to outer auditory nerve fibers causes high-frequency hearing loss
• Deficits at lower perceptual levels propagate upward through Erber’s hearing hierarchy
• Degraded interaural timing coding, not audiometric asymmetry, explains reduced MLD in hearing loss.
• Different auditory nerve fiber types have distinct response thresholds.
• Different-sex background voices boost speech intelligibility by up to 40 percent at low SNRs
• Diotic listening rarely occurs because the two ears receive different signals in daily life
• Diplacusis affects normal-hearing listeners too, at 1-2% pitch discrepancy
• Directional hearing aid microphones can degrade sound localization by attenuating lateral sounds
• Directional microphones trade speech clarity for degraded sound-localization cues
• Directive microphone arrays in hearing aids improve speech intelligibility in noise
• Double-vowel tasks isolate f0 differences as cues for separating simultaneous speech
• Ear separation on one axis makes horizontal binaural cues strongest
• Earliest arriving sound dominates localization despite later room reflections
• Earliest hearing-loss tests measured duration and distance of audibility
• Early 20th-century hearing research was steered by telephone engineering needs.
• Early audiogram standardization debates concerned level units and axes, not frequency scaling.
• Early cochlear measurements were distorted by post-mortem damage
• Early commercial audiometers cost about $25,000 in modern currency, driving a portable redesign.
• Early hearing-loss assessment relied on tuning-fork duration and distance thresholds.
• Early otosclerosis adds stiffness and thus selectively reduces low-frequency hearing
• Early psychoacoustics lacked tools to control sound intensity independently of frequency
• Early psychoacoustics neglected loudness because sound intensity could not yet be controlled.
• Echo thresholds vary widely and do not correlate with audiometric thresholds in hearing loss.
• Echo-fusion thresholds vary widely among hearing-impaired listeners regardless of audiometric thresholds.
• Elevated gap detection thresholds in hearing loss stem from threshold elevation, not temporal pathology
• Elevated hearing thresholds degrade speech perception by rendering key cues inaudible
• Energetic and informational masking operate through distinct peripheral and central mechanisms
• Equal objective differences loom larger when they involve smaller baseline amounts
• Equal-loudness contours reflect outer and middle ear amplification characteristics.
• Equal-loudness-contour weighting schemes failed as loudness meters
• ERB is the standard metric for auditory filter bandwidth
• Euclid anticipated Helmholtz’s definition of consonance and dissonance
• Eustachian tube blockage causes pain and low-frequency hearing loss
• Even slight hearing losses of 16-25 dB HL may benefit from hearing aids.
• Even small asymmetries between ears reduce binaural summation
• Even small hearing asymmetries across ears disrupt binaural hearing.
• Exaggerated hearing loss appears as an overly conservative response bias during audiometry
• Excitation pattern differences grow with filter frequency, favoring the high-frequency edge
• Excitation patterns smooth the spectrum, blurring harmonic and formant detail the acoustic signal carries
• Experiments isolating two-ear advantages must present stimuli over headphones
• Faster modulation triggers ear’s temporal integration while slower modulation engages short-term memory
• FDL findings compromise a purely temporal account of low-frequency pitch.
• Fechner made conscious perception measurable and founded experimental psychology
• Fechner made perception measurable by tying it mathematically to physical stimuli
• Fiber-type-specific damage produces distinct loudness perception abnormalities.
• Filter cutoff frequency is conventionally the 3-dB-down point.
• Fletcher and Munson pioneered equal-loudness contours in 1933 via loudness balancing.
• Fletcher and Munson’s 1933 loudness data remain essentially accurate today.
• Fletcher originated threshold measurement, loudness relations, and masking models
• Fluctuating maskers produce masking release that Fletcher’s power spectrum model cannot explain.
• Forced-choice paradigms cancel out listener response criterion across intervals
• Forced-choice paradigms hide the signal in a randomly chosen interval
• Forced-choice paradigms present one signal amid two or more observation intervals.
• Forced-choice testing cancels listener response criterion effects in threshold estimation
• Forward masking and gap detection measure the same resolution differently
• Forward masking avoids the nonlinear effects that only arise from simultaneity.
• Forward masking decay slows markedly after masker offset in hearing loss
• Forward masking measures temporal processing between distinct sounds.
• Forward masking presents masker before signal so the two never overlap in time
• Forward masking requires maskers with similar frequency components and high intensity
• Forward masking reveals an effect that only appears when sounds co-occur.
• Forward masking reveals how the ear’s perceptual representation of sound decays over time
• Forward-masking recovery is slower in sensorineural hearing loss regardless of audibility
• Free-field hearing thresholds can exceed headphone thresholds by over 15 dB
• Free-field threshold testing yields thresholds 15 dB better than headphones
• Frequency importance functions weight speech audibility by band significance
• Frequency selectivity in normal-hearing listeners worsens at high sound levels
• Frequency selectivity is the auditory system’s ability to represent one frequency independently of another.
• Frontal minimum audible angle is about one degree for low frequencies
• Fundamental frequency differences between voices improve speech intelligibility
• Fundamental frequency is coded dually via harmonics and envelope rate
• Gap added to a tone creates audible spectral splatter or side lobes.
• Gap detection acuity improves with presentation level up to about 30 dB SL.
• Gap detection and amplitude modulation are usually intact after sensorineural loss
• Gap detection experiments vary in whether listeners report a gap or count of sounds
• Gap detection improves with bandwidth because the ear listens across more auditory filters
• Gap detection measures only on-off discrimination and misses fluctuation-rate coding
• Gap detection measures only on-off sensitivity, not coding of fluctuation rates.
• Gap detection measures the smallest audible silent gap
• Gap detection offers quick but shallow measures of temporal acuity
• Gap detection tasks measure how the ear follows temporal changes relevant to communication
• Gap detection thresholds improve sharply with level up to about 30 dB SL
• Gap detection thresholds improve with increasing stimulus bandwidth but not frequency region
• Glimpses can fall below audibility threshold for hearing-impaired listeners
• Graph scaling choices shape the inferred form of loudness functions.
• Gustav Fechner mathematically formulated the law named after his mentor Weber.
• Harmonic amplitudes shape timbre and loudness but not pitch.
• Harmonic tones are integer multiples of a fundamental frequency
• Harmonics are integer-related partials while partials need not be harmonic
• Harvey Fletcher pioneered threshold measurement, loudness relations, and the masking model.
• Harvey Fletcher shaped modern psychoacoustics and audiology at Bell Labs
• Hawkins and Stevens measured broadband-noise masking of pure tones across eight masker levels.
• Head movement and pinna shape resolve cone-of-confusion ambiguities
• Head movements and pinna shape resolve ambiguous sound localization
• Head shadow attenuates sound arriving at the far ear unless the source is centered
• Head shadow gives one ear a better signal-to-noise ratio in typical listening
• Head shadow makes high-frequency binaural cues inaudible in sloping hearing loss
• Head-related transfer functions encode all body-induced spectral and temporal sound changes
• Headphone experiments measure binaural summation by stimulating each ear independently
• Headphone experiments reveal auditory abilities that free-field studies cannot expose.
• Headphone presentation is required to measure true binaural benefit
• Headphone studies reveal ILD perception abilities hidden by natural field acoustics
• Headphones allow separating interaural phase from interaural time delay
• Healthy ears exploit gaps in fluctuating maskers better than steady ones
• Hearing aid algorithms distort auditory cues yet still improve speech understanding
• Hearing aid compression maps a wide input range into a narrower output range
• Hearing aid compression that distorts timing can make stop consonants harder to distinguish.
• Hearing aids address three deficits but leave frequency, temporal, and pitch processing unaddressed.
• Hearing aids cannot restore sound localization because coding damage, not audibility, is the cause
• Hearing aids cannot restore sound localization but may aid ILD representation.
• Hearing aids distort localization cues and often worsen localization
• Hearing aids fail to restore sound localization in many listeners
• Hearing aids often worsen rather than improve sound localization.
• Hearing depends on sequential physiological stages, each with distinct perceptual consequences when damaged.
• Hearing impairment disrupts both place and temporal pitch codes
• Hearing loss acts like a filter attenuating specific frequencies
• Hearing loss correlates weakly with precedence-effect echo thresholds.
• Hearing loss disrupts pitch perception through multiple independent coding failures
• Hearing loss disrupts pitch via place, temporal, and interaural mechanisms.
• Hearing loss does not change the psychometric function’s 12-dB detection range
• Hearing loss extends internal masker persistence and shrinks duration benefits
• Hearing loss impairs frequency selectivity beyond what stimulus level differences explain.
• Hearing loss impairs masking through three compounding spectral mechanisms
• Hearing loss is a sensory-representation deficit, not merely an acoustic one.
• Hearing loss reduces audibility and restricts usable bandwidth for temporal processing
• Hearing loss reduces the effect of inherent noise fluctuations on speech masking.
• Hearing loss squeezes the full loudness range into a much smaller dynamic range
• Hearing loss was first quantified as a percentage of remaining dynamic range
• Hearing the same tone at a different pitch in each ear is called diplacusis
• Hearing thresholds were first systematically mapped in the 1930s using two distinct measurement paradigms
• Hearing-impaired frequency discrimination does not correlate with audiogram or frequency selectivity
• Hearing-impaired listeners benefit roughly two-thirds less from binaural squelch than normal-hearing listeners.
• Hearing-impaired listeners gain far less binaural-squelch advantage than normal hearers
• Hearing-impaired listeners gain half or less benefit from longer stimulus durations
• Hearing-impaired listeners show faster loudness growth but similar discomfort thresholds
• Hearing-impaired listeners show intact gap detection but prolonged forward masking that hides consonants
• Hearing-impaired listeners usually hear the correct pitch but with more variability
• Hearing-impaired listeners vary widely in binaural deficit severity
• Hearing-impaired perception studies illuminate the mechanisms behind normal hearing
• Hearing-loss severity categories lead patients to underestimate their communication difficulties
• Helmholtz made the first psychoacoustic observations in hearing
• Helmholtz’s place theory failed to explain all pitch phenomena, prompting more complex models.
• Helmholtz’s place theory says pitch derives from the basilar membrane’s location of maximum excitation.
• High bass levels are safe while comparable high-frequency levels risk hearing.
• High modulation detection thresholds signal poor temporal representation of those rates.
• High spontaneous-rate fibers have low thresholds while low SR fibers have high thresholds.
• High spontaneous-rate nerve fibers have low thresholds and vice versa
• High-frequency interaural phase differences are ambiguous about azimuth location
• High-frequency sounds reflect off the head while low-frequency sounds diffract around it
• High-frequency tones produce ambiguous azimuthal localization due to phase wrapping.
• High-frequency tones yield multiple possible source locations from a single phase difference
• Higher F0 reduces pitch resolvability because harmonics interact less within a filter.
• Higher-frequency auditory filters carry more intensity-difference information than the signal-centered filter
• Horizontal-plane localization needs no listener-specific HRTF, but vertical does
• Humans discriminate level differences of under half a decibel across a 100 dB range
• Hyperacusis is a separate pathology from sensorineural hearing loss
• Identical ITDs form a 3D cone producing ambiguous source location.
• Identifying a vowel requires at least two of its formants
• Impaired frequency selectivity and lost suppression increase masking and reduce spectral contrasts
• Impaired frequency selectivity, suppression, and fluctuation use jointly degrade hearing
• Impaired pitch perception hampers understanding speech amid background noise
• In signal detection theory, threshold responses depend on an internal response criterion reflecting bias.
• Increasing intensity improves frequency discrimination, much more at low frequencies
• Increasing stimulus level broadens auditory filters and causes upward spread of masking
• Independent compression in each ear distorts binaural localization cues
• Individual auditory nerve fibers cannot code the full hearing dynamic range
• Individual hearing-impaired listeners compensate by relying on whichever pitch code remains intact
• Individualized HRTFs only improve localization in planes requiring pinnae cues
• Inherent noise fluctuations do not universally limit speech perception across hearing conditions
• Inserting a temporal gap into a stimulus produces spectral splatter at the gap edges
• Intense forward maskers produce both more masking and more release
• Intensity discrimination improves with level for tones, violating Weber’s law
• Intensity discrimination JND is expressed as the intensity-based Weber fraction.
• Intensity discrimination measures the smallest detectable change in loudness
• Intensity is directly quantifiable acoustically while loudness requires human listeners
• Interaural level differences grow with frequency and reach up to 20 dB.
• Interaural level differences grow with frequency and side placement
• Interaural noise correlation inversely drives the magnitude of binaural release from masking.
• Interaural phase difference varies with frequency while interaural time difference does not
• Interaural phase discrimination is finest at midline and low frequencies
• Inverting signal phase at one ear vastly releases speech from masking.
• ITDs are frequency-independent physically yet frequency-dependent perceptually.
• Just noticeable differences are proportional to baseline stimulus size
• Lack of intensity-measuring instruments shaped early psychoacoustic research priorities
• Larger baseline weights require proportionally larger differences to be noticed
• Level-dependent frequency discrimination contradicts a purely temporal pitch code
• Listeners benefit from spectral profiles bandwidth-wide yet do not use all available spectral information
• Listeners detect signals by comparing internal responses against a learned decision criterion.
• Listeners identify melodies perfectly using only temporal information because amplitude-modulated noise can encode pitch
• Listeners use distributed spectral information but not all of it
• Listeners with hearing loss form a heterogeneous perceptual group, not a single category
• Live cochleas are much more sharply tuned than cadaver measurements suggested
• Longer pure-tone durations produce narrower spectral peaks with less splatter
• Loss of cochlear suppression explains similar PTCs across masking conditions.
• Loud speech sounds can mask quieter ones within the same utterance for hearing-impaired listeners
• Loudness as perception can never be directly measured physiologically
• Loudness balancing measures loudness by matching a test sound’s level to a reference
• Loudness cannot be explained by single auditory nerve fiber firing alone
• Loudness coding requires pooled responses across many auditory nerve fibers
• Loudness discomfort levels are measured to fit hearing aids and assess hyperacusis
• Loudness grows as a power law of intensity, not linearly.
• Loudness growth with intensity requires experimental quantification, not intuition
• Loudness is a psychological percept measurable only through human report
• Loudness is measured either by rating magnitude or by matching equal loudness
• Loudness is not reducible to sound pressure level or signal power
• Loudness is perceptual and unmeasurable directly, while intensity is acoustic and directly quantifiable
• Loudness is perceptual while intensity is physical and must be distinguished
• Loudness is the summed specific loudness across critical-band rates, not the raw spectral level
• Loudness lacked any measurement tool or unit until Stevens invented both.
• Loudness models can guide hearing aid programming and alarm design
• Loudness models estimate total neural activity since it cannot be measured directly
• Loudness perception involves central mechanisms beyond cochlear vibration
• Loudness perception is not solely peripheral vibration but involves central auditory transformation.
• Loudness recruitment makes raised speech feel too loud even without abnormal sound perception
• Loudness recruitment shrinks dynamic range while preserving overall loudness
• Loudness-growth slope increases with hearing-loss degree but resists exact prediction
• Low harmonics are resolved in the excitation pattern but smear beyond the tenth harmonic.
• Low sensation level impairs ITD and ILD discrimination even in normal listeners
• Low-frequency maskers mask high-frequency signals more than the reverse, and this worsens with intensity.
• Low-level auditory deficits cascade upward to impair speech comprehension
• Lower-level auditory deficits cascade upward but not all higher-level deficits trace downward.
• Magnitude estimation lets listeners assign numbers proportional to perceived loudness.
• Magnitude estimation of loudness yields only relative, not absolute, values.
• Masker effectiveness is determined solely by power falling within one auditory filter.
• Masking depends on acoustic relationships between masker and signal, not on subjective noise.
• Masking depends on stimulus fluctuations in ways steady-state models cannot predict.
• Masking effectiveness depends on masker-signal power, frequency, and timing relationships
• Masking effectiveness depends only on masker power inside the critical band.
• Masking experiments infer auditory representation from masker effects on signals.
• Masking experiments revealed the auditory filter underlying frequency selectivity
• Masking is quantified as the threshold elevation a masker produces.
• Masking is quantified as the threshold shift between unmasked and masked conditions.
• Masking occurs when one sound interferes with perceiving another
• Masking patterns reveal the ear’s internal psychological representation of a sound.
• Masking release differences shrink when normal listeners are tested at matched sensation level
• Masking release from modulated noise also improves speech perception.
• Melodic interval identification degrades once about 9-10 harmonics are removed
• Middle ear stiffness reduces low-frequency gain while added mass reduces high-frequency gain
• Middle-ear stiffness increases cause low-frequency hearing loss
• Mild and severe hearing losses produce opposite loudness growth patterns
• Mild-moderate losses show recruitment while severe-profound losses show underrecruitment
• Miller’s 1947 study tested Weber’s law with noise stimuli
• Minimum audible field and pressure measurements differ in listening conditions and calibration.
• Missing fundamental pitch survives even when cochlear distortion is masked out
• Missing otoacoustic emissions reveal conductive or cochlear but not retrocochlear defects
• Modern audiology rests on the premise that perception connects to physics
• Modern pitch research relies on discrimination tasks because subjective pitch ratings are problematic
• Modulation depth m ranges from unmodulated to fully modulated sounds
• More compression channels reduce spectral contrast and vowel recognition
• More hearing aid compression channels measurably degrade vowel perception in hearing-impaired listeners.
• Narrow-band devices like telephones degrade temporal cue coding and raise listening effort
• Narrowband noise needs bandwidth and center frequency descriptors
• Narrowband noise requires bandwidth and center frequency parameters beyond power.
• Narrowband noise’s natural waveform fluctuations mask the presence of inserted gaps
• Narrowband noises contain fewer frequencies and show greater amplitude fluctuations than broadband noise.
• Narrowband noises fluctuate more than wideband stimuli, making them useful for studying fluctuation coding
• Narrower noise bandwidths produce slower amplitude fluctuation rates
• Near miss to Weber’s law occurs for tones but not noise
• Near-threshold sounds may sound louder to impaired than to normal ears
• Neither conservative nor liberal response bias yields accurate hearing thresholds
• Neural information is encoded in the patterning of voltage spikes
• Newborn hearing screenings deliberately accept false positives to avoid missing true hearing loss
• No single auditory nerve fiber spans the full dynamic range of human hearing.
• No single standard metric describes auditory intensity discrimination
• Noise can damage high-threshold auditory fibers while audiograms still look normal
• Noise gates and compression let aids make faint speech audible without amplifying noise
• Noise intensity discrimination improves by pooling multiple frequency regions
• Noise is defined relationally against the signal rather than acoustically
• Nonlinear hearing aid amplification partially restores distorted loudness perception.
• Normal-hearing listeners exploit temporal dips in fluctuating maskers to detect signals.
• Not all sounds have a pitch even though all have frequency content
• Only low-numbered harmonics are resolved, higher ones blur together in the internal representation
• Only masker power within the critical band around a signal affects its threshold
• Only simultaneous masking arises in cochlear peripheral processing
• Ossicular mass increases from otosclerosis cause high-frequency hearing loss
• Outer and middle ear damage changes the loudness frequency balance
• Outer and middle ear structures provide frequency-specific amplification of incoming sound
• Outer and middle ear transfer function determines loudness across frequency.
• Outer hair cell damage removes cochlear compressive nonlinearity
• Outer hair cell damage steepens the basilar membrane’s growth function
• Outer hair cell loss is the primary driver of loudness recruitment
• Outer hair cell loss reduces hearing sensitivity by up to 60 dB
• Patient false positives signal a reasonable response criterion, not poor performance
• Peak amplitude misrepresents complex sounds with varying amplitude
• Perceptual deficits correlate poorly with audiogram thresholds and vary widely
• Perceptual impairments directly cause speech perception problems in natural environments
• Period histograms reveal phase locking by plotting spike counts across stimulus phase.
• Period histograms visualize neural firing synchrony by spike phase
• Phase delays beyond 180 degrees make direction judgments ambiguous
• Phase-based directional hearing works only below about 743 hertz
• Physiological coding of frequency does not by itself explain perceived pitch.
• Physiological measures alone cannot prove how pitch perception works
• Physiological tests measure neural representation, not actual hearing
• Physiological tests measure sound representation, never the perception itself
• Pinna cues drive the need for individualized HRTFs in vertical localization
• Pinnae shape the sound spectrum to encode elevation and front-back position
• Pitch arises from where along the cochlea a sound maximally stimulates
• Pitch can be derived from harmonic spacing even without the fundamental present.
• Pitch can only be measured relative, not absolutely
• Pitch cannot be measured absolutely, only relative to another tone
• Pitch cues convey identity, intonation, and emotion beyond mere speech content
• Pitch differences enable selective listening to one talker amid competing voices
• Pitch enables voice identification and the cocktail party listening effect
• Pitch has no magnitude like loudness, so magnitude scaling misapplies to it.
• Pitch is coded by different mechanisms above and below roughly 3 kHz
• Pitch is formally defined as where sounds fall on a musical scale
• Pitch is perceptual while frequency is acoustic, and not all sounds have pitch
• Pitch is the perceptual property ordering sounds from low to high
• Pitch lacks a magnitude dimension, complicating its subjective measurement
• Pitch may be jointly coded by temporal patterns and their cochlear location
• Pitch of harmonic sounds is determined by the fundamental frequency.
• Pitch perception deficits from hearing loss impair speech segregation from noise.
• Pitch perception involves both spectral and temporal representations of sound
• Pitch shifts with intensity but individual listener variability is large.
• Pitch strength is a distinct perceptual dimension absent from loudness
• Place and temporal codes each offer distinct neural mechanisms for extracting pitch
• Place and temporal codes work together and must stay synchronized for accurate pitch.
• Place code governs pitch perception of pure tones above about 4 to 5 kHz
• Place coding of fundamental pitch fails at high frequencies when harmonics smear together
• Place coding poorly carries pitch when harmonics go unresolved.
• Pooled neural firing encodes stimulus period as spike intervals.
• Poor frequency selectivity causes speech-in-noise difficulty and complicates hearing aid fitting
• Precision medicine may soon tailor treatment to individual perceptual disorder profiles
• Prescriptive rule choice hardly affects speech intelligibility outcomes
• Presenting speech at the same loudness minimizes forward-masking differences
• Processing spectral peaks and valleys in separate compression channels erases their level difference
• Prolonged forward masking makes vowels mask consonants in impaired ears
• Pseudohypacusis is essentially an overly conservative detection criterion
• Pseudohypacusis reflects an overly conservative response criterion under signal detection theory.
• Psychoacoustic retrocochlear tests have good specificity but poor sensitivity.
• Psychoacoustics explains perception through physiological mechanisms
• Psychoacoustics measures detection, discrimination, magnitude, and recognition of sounds
• Psychoacoustics originated in early 1700s experimental psychology
• Psychoacoustics traces its roots to eighteenth-century philosophers.
• Psychophysical tuning curves map masker level needed to just mask a fixed tone.
• Psychophysical tuning curves measure frequency selectivity via tone-on-tone masking.
• Pure tones are used for audiometry because they are frequency-specific
• Pure-tone localization errors spike specifically around 2000 to 4000 Hz
• Pure-tone temporal coding is low-frequency only, but complex tones use both fiber types.
• Pure-tone Weber functions slope downward across all tested frequencies
• Quiet-versus-narrowband-masked AM threshold differences can isolate temporal coding from cochlear compression
• Raising intensity lowers pitch at low frequencies but raises it at high frequencies.
• Random intensity variation disrupts place but not temporal pitch coding
• Rayleigh first proposed ILDs code high frequencies and ITDs code low frequencies
• Re-instructing suspected feigners shifts their decision criterion toward true thresholds
• Reaction time measures loudness across the full hearing range
• Reaction time measures loudness in animals and language-disabled people
• Reaction time spans the full hearing range where psychometric functions cover only 10-15 dB
• Recruitment-induced loudness discomfort in aided listeners is a level artifact, not hypersensitivity
• Reduced dynamic range forces nonlinear amplification to avoid over-amplifying loud sounds
• Reduced dynamic range makes linear hearing aid amplification unsafe
• Reduced frequency selectivity hurts speech perception less than reduced audibility does
• Reliable perception measurement emerged only in the early 1800s
• Removing harmonics degrades f0 discrimination but it stays precise without them
• Removing low harmonics from a complex tone leaves its pitch unchanged.
• Reported pitch-with-intensity shifts vary widely with method
• Research staircase methods require start level, step, and stop criteria
• Residue pitch is computed in the auditory cortex within a tenth of a second
• Resolved harmonics use place pitch coding while unresolved harmonics use temporal coding
• Resolved low-numbered harmonics are required to encode pitch by place
• Response bias can contaminate any psychophysical threshold estimate
• Response bias distorts threshold measurements in hearing experiments.
• Response bias shifts audiometric thresholds away from a patient’s true hearing abilities
• Restoring audibility does not restore sound localization in hearing loss
• Rollover signs make loud amplification harmful to retrocochlear patients
• Same-sex background voices mask speech for listeners of either sex.
• Self-adjustment threshold methods are fast but lack a standardized response criterion across listeners.
• Sensorineural hearing loss causes abnormal rapid loudness growth called recruitment
• Sensorineural hearing loss compresses the full loudness range into fewer decibels
• Sensorineural hearing loss damages pitch, harming speech-in-noise communication
• Sensorineural hearing loss disrupts some temporal abilities but not others, with wide individual variability
• Sensorineural hearing loss impairs binaural cue use more than basic audibility
• Sensorineural hearing loss produces rapid loudness growth while discomfort thresholds stay normal
• Sensorineural hearing loss reduces temporal integration benefit by half or more
• Sensorineural hearing loss worsens diplacusis, which even normal hearers have mildly
• Sensorineural hearing loss worsens masking beyond mere threshold elevation
• Separate compression channels for peak and valley reduce spectral contrast
• Separating a signal from a competing noise location aids detection beyond diotic summation
• Separating signal from masker locations improves detection through two binaural effects
• Severe hearing loss from inner hair cell loss reduces maximum loudness
• Short sound durations necessarily produce broad frequency bandwidths.
• Short tones smear extra frequencies into their spectra, a cost called spectral splatter.
• Shorter sounds necessarily have broader spectral bandwidths
• Signal detection theory models signals and noise as two probability distributions
• Signal Detection Theory principles help audiologists extract true thresholds from feigning patients
• Similar critical duration does not imply normal temporal integration in hearing loss
• Similar critical durations do not imply normal temporal integration
• Similar frequencies mask each other by competing for the same cochlear location.
• Simulated loudness recruitment harms speech intelligibility but hearing-aid compensation does not restore it
• Simultaneous masking yields broader tuning curves than forward masking.
• Simultaneous synthetic vowels can be separated by their fundamental frequencies alone.
• Simultaneous-masked PTCs are broader than forward-masked PTCs, with similar overall shape
• Simultaneous-masking filters may understate the ear’s true spectral resolution
• Slow release from forward masking impairs comprehension of rapid speech.
• Small detection-threshold gains amplify into much larger identification-level changes
• Smaller step sizes in audiometry detect feigned hearing loss
• Soft sounds give the ear inadequate access to rapid amplitude changes in speech
• Some false positives during threshold testing indicate healthy response bias
• Sound level meters measure pressure, from which intensity is derived
• Sound localization deficits in hearing loss come from neural coding changes, not audibility.
• Sound localization is best for frontal sounds and at low and high frequencies
• Sound localization is most accurate when facing the sound source
• Sound location is mapped with azimuth and elevation coordinates
• Sound perception decays slowly and can mask a following sound
• Sound pressure and intensity are distinct quantities interconvertible by a known relationship
• Sound pressure and intensity relate through air impedance of roughly 415 rayls
• Sound’s wavelength determines whether it reflects off the head or diffracts around it
• Sounds are time-varying when their intensity changes over time
• Sounds missing many harmonics still evoke a weak pitch sensation
• Spectral valleys contribute little to vowel identification compared with formants
• Speech intelligibility can be predicted by measuring signal envelope modulation decay
• Speech intelligibility depends on which frequency bands matter for specific materials.
• Speech reception thresholds closely duplicate averaged audiometric thresholds
• Speech understanding benefits when the signal is phase-inverted at one ear.
• Staircase rules specify how many correct trials precede a level decrease
• Standard audiological tests miss most of the perceptual abilities humans need to communicate
• Standard clinical threshold testing estimates the 85-95% detection point
• Stevens anchored the sone unit to a 1000-Hz tone at 40 dB SPL.
• Stevens defined one sone as a 40 dB SPL 1000-Hz tone
• Stevens had to invent both the tools and the unit for measuring loudness
• Stevens measured pitch shifts of up to 15-20% with changing intensity.
• Stimulus envelope, not temporal fine structure, counts as temporal information
• Stimulus fluctuations hurt gap detection but aid speech perception elsewhere
• Stimulus level is coded by firing rate plus the pattern across fiber types
• Successful communication requires multiple distinct auditory perception abilities beyond simple detection.
• Telephone technology enabled precise measurement of sound perception
• Temporal codes yield weak pitches compared to place codes
• Temporal fine structure is vital yet not perceived as a temporal event
• Temporal integration models divide on time constant assumptions of hundreds versus single-digit milliseconds.
• Temporal integration up to 200 ms approximates masking for in-band signals
• Temporal modulation detection is independent of hearing threshold
• Temporal modulation transfer functions give broader resolution data but slowly
• Temporal modulation transfer functions trade completeness against measuring time
• Temporal order thresholds exceed gap detection because listeners must hold sound identities in memory
• Temporal processing deficits undermine speech understanding and music appreciation
• Temporal processing is essential for hearing speech and music
• Temporal processing of sound has three distinct measurable categories.
• The 1935 Beasley survey first established US normal-hearing thresholds
• The audiogram cannot predict which hearing-impaired listeners have temporal processing deficits
• The audiogram does not predict pitch perception deficits in hearing loss
• The audiogram fails as a robust indicator of perceptual deafness deficits
• The audiogram is a behavioral test rooted in a century of psychoacoustics
• The audiogram measures only detection and conceals varied sensorineural perceptual deficits.
• The audiogram measures only detection thresholds, so it misses everyday speech-in-noise ability.
• The audiogram measures only sound detection, not other auditory perceptions
• The audiogram only captures detection thresholds and fails to predict real-world speech perception
• The audiogram’s form was contested because no standard existed for its axes.
• The audiogram’s inverted axis breaks standard scientific plotting convention
• The auditory system acts as a band-pass filter at each signal frequency.
• The auditory system can discard uninformative noise and use only informative samples for detection
• The auditory system can extract pitch from resolved low-frequency harmonics using place patterns
• The auditory system lacks robust access to interaural phase above 1000 Hz
• The auditory system represents modulations below 55 Hz well and worse above
• The auditory system’s ~120 dB dynamic range exceeds any single nerve fiber’s coding capacity
• The band-widening paradigm measures signal threshold while varying masker bandwidth
• The basilar membrane’s logarithmic spacing justifies plotting auditory representations on log frequency axes
• The better-ear advantage alone yields an 8 dB SRT benefit worth 56 percentage points
• The better-ear advantage yields an 8 dB speech-recognition benefit in noise
• The choice of hearing aid prescriptive rule barely affects speech intelligibility.
• The cone of confusion makes identical ITDs map to many indistinguishable locations
• The cone of confusion prevents up-down and front-back sound discrimination
• The critical band model fails because selectivity varies with level and asymmetry.
• The decibel unit enabled standardized hearing characterization
• The dynamic range of hearing is largest between 500 and 6000 Hz
• The ear analyzes frequencies by location along the basilar membrane.
• The ear cannot sense a tone’s absolute phase but does sense phase differences.
• The ear integrates energy over time to lower detection thresholds for longer sounds
• The ear switches from place to temporal pitch coding when harmonics stop being resolved
• The ear’s frequency resolution worsens progressively at higher frequencies.
• The ear’s frequency selectivity is imperfect and worsens at higher frequencies
• The ear’s frequency selectivity worsens as frequency rises above 500 Hz.
• The energy detector model fails because it accumulates interfering noise along with signal energy.
• The excitation pattern is the internal representation of a stimulus spectrum
• The excitation pattern plots auditory-filter output power against filter center frequency
• The existence region supports a place-based harmonic template model of pitch
• The frequency-pitch mapping was established before models of pitch existed
• The full loudness range squeezes into a smaller dynamic range for impaired listeners.
• The harmonic overtone series of strings is a lucky gift, not a fixable property
• The JND is the smallest intensity change the ear can discriminate
• The just-detectable speaker shift defines the minimum audible angle.
• The lateral superior olive compares ear intensities via excitation and inhibition
• The loudness-intensity relationship is named Stevens’ power law.
• The mel scale appears discredited but its underlying effects still hold
• The mel scale defines pitch by assigning 1000 mels to a 1000-Hz tone
• The mel scale is largely discredited yet remains used in speech and acoustics
• The method of adjustment is flexible but yields listener-dependent thresholds
• The method of constant stimuli needs prior knowledge of testable levels
• The method of limits estimates thresholds by averaging ascending and descending detection levels
• The mid-frequency hearing advantage explains why alarms and speech amplification target 1000-6000 Hz.
• The minimum audible angle quantifies the just-detectable change in sound source position
• The near miss to Weber’s law results from off-frequency auditory filters coding intensity
• The near miss to Weber’s law results from the ear using spread-of-excitation across frequency
• The notched-noise method directly measures auditory filter shape.
• The outer and middle ear, not the cochlea, shape the absolute threshold curve.
• The place code alone explains pure-tone pitch above 4-5 kHz.
• The precedence effect reduces masking from reflections in rooms
• The range of SNRs contributing to speech intelligibility is wider than SII standards assume
• The residue pitch refuted Helmholtz’s place theory of pitch percept.
• The shape of the audiogram reflects outer and middle ear transfer, not cochlear transmission
• The telephone industry drove development of technologies for measuring hearing.
• The temporal code mainly handles pitch at low frequencies where pitch is strong
• The temporal modulation transfer function broadly characterizes temporal acuity.
• The term UCL fits the measurement better than LDL, yet US practice favors LDL
• The Weber fraction for frequency declines below 1500 Hz then rises above 2000 Hz
• There is a critical bandwidth beyond which adding noise power no longer increases masking
• Three acoustic properties determine whether a sound masks another.
• Three distinct perceptual phenomena define the precedence effect.
• Threshold estimates reflect both ear sensitivity and listener response bias
• Threshold from up-down staircases is the averaged level at response reversals.
• Threshold is a statistical artifact, not a sharp boundary of audibility
• Threshold measurement method, not listener differences, caused the 10 dB gap
• Thresholds are statistical detection probabilities, not absolute cutoffs
• Time and frequency representations are linked so short durations broaden bandwidth
• Time-shifting an identical noise masker changes consonant perception measurably.
• Tinnitus character signals underlying medical conditions
• Tinnitus has no objective diagnostic test and is diagnosed by self-report alone
• Tinnitus is the top service-connected military disability yet lacks any diagnostic test.
• Tinnitus loudness matches do not predict tinnitus annoyance or diagnostic value
• Tinnitus loudness matches fall 5 to 15 dB above audiometric threshold
• Tinnitus loudness typically sits 5-15 dB above threshold yet does not predict annoyance.
• Tinnitus pitch spans the entire region of hearing loss, not a single frequency
• Tones confound gap detection with spectral-change detection.
• Topic-based organization beats sequential background chapters for teaching audiology
• Tuning curves map the lowest level that evokes neural or basilar response
• Two ears give small but consistent gains across all auditory tasks
• Two ears improve detection, localization, and masking resistance over one.
• Two ears yield summation, localization, and echo suppression jointly
• Two noises with equal LPC differ in total power by their bandwidth
• Two separated tone pulses aid detection more than one, unaffected by intervening noise level
• Two-ear listening improves sound-field thresholds by 10 to 15 dB
• Two-tone suppression makes simultaneous masking appear broader than forward masking
• Undefined observation intervals prevent patients from anticipating signals and biasing thresholds low
• Unresolved harmonics smear together as frequency rises
• Variable-frequency experiments reveal frequency effects that fixed-frequency masking hides.
• Voice differences include formant and temporal cues beyond fundamental frequency
• Von Békésy’s tuning curves were broadened by post-mortem cochlear damage.
• WDRC processing distorts the temporal cues hearing-impaired listeners rely on for stop consonants
• Weber fraction for tones is level but not frequency dependent
• Weber fractions in audition are computed from intensity, not decibels
• Weber’s law holds for noise discrimination above 20 dB sensation level.
• Weber’s law holds for noise intensity discrimination above about 20 dB SL
• Weber’s law states JND is a constant fraction of stimulus magnitude
• Whether loudness recruitment degrades speech perception remains unsettled
• White noise amplitude is described by total power or spectrum level (LPC).
• White noise carries constant power per hertz across the human hearing range
• White noise has flat power across the 20 to 20,000 Hz hearing range
• White noise is not a valid stimulus to assess gap perception.
• White noise masks the spectral artifacts a gap would otherwise introduce.
• Wide bandwidth improves temporal perception while low-pass filtering limits it
• Wide bandwidth noise sounds as loud as a narrower tone despite lower level
• Wide dynamic range compression degrades perception of speech temporal cues like stop consonants
• Wide dynamic range compression typifies all nonlinear hearing aid amplification
• Wideband sounds are louder than narrowband sounds at equal dB SPL
• Widening modulated-noise bandwidth can paradoxically lower detection thresholds.
• Wider auditory filters admit excess noise that fully obscures high-frequency formants
• Wider auditory filters let noise obscure formants entirely in impaired ears.
• Wider bandwidth increases perceived loudness at equal sound pressure
• Wider peripheral tuning from hearing loss suppresses low-frequency fluctuation amplitude
• Wider stimulus bandwidth improves the ear’s temporal acuity
• Wider stimulus bandwidths improve listeners’ ability to detect temporal gaps
• Within-speech forward masking hampers consonant identification for hearing-impaired listeners
• Word recognition that declines with louder speech signals retrocochlear pathology.
• Wundt built drop-based devices isolating intensity from frequency for controlled study.
• Wundt founded experimental psychology as separate from biology and philosophy
• Zero false positives during threshold testing signals feigned hearing loss