Two-tone suppression lets strong signal components override weaker nearby ones

Evidence

Sound of a given frequency can block our ability to hear softer sounds at nearby frequencies, but distant frequencies are not affected. The threshold for detecting the softer sound is raised by the presence of a louder sound within the same critical bandwidth. Even if the softer sound is audible, it will not seem as loud as it would if played alone. Similarly, two tones that fall within the same critical bandwidth will appear to be less loud together than two tones of the same total energy that fall outside each others’ critical bandwidths. — Eric J. Heller, Why You Hear What You Hear- An…, 2009 (#qualifies, via linked claim)

When two or more pure tones are heard together an effect known as “masking” can occur, where each individual tone can become more diffi­ cult or impossible to perceive, or it is partially or completely “masked,” due to the presence of another tone. In such a case the tone which causes the masking is known as the “masker” and the tone which is masked is known as the “maskee.” These tones could be individual pure tones, but, given the rarity of such sounds in music, they are more likely to be individual fre­ quency components of a note played on one instrument which mask either other components in that note, or frequency components of another note. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1628 (#exemplifies, via linked claim)

This suggests that suppression estimates were significantly greater when measured with a short combined masker. It is possible that the decreased suppression in the older adults was due to their increased auditory thresholds. To determine the effect of auditory threshold on suppression estimates, correlation coefficients were computed between threshold in dB HL and suppression estimates from each of the eight conditions tested. Out of the eight suppression conditions, threshold at 2 kHz was negatively correlated with low-side suppression at the 50-dB SPL signal level measured with the short combined masker [r (10) = − 0.68, p = 0.031] and with the long combined masker [r (10) = − 0.67, p = 0.33]. — Dijk, Pim van, Physiology, Psychoacoustics and…, 949 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Narrowband noise at a given frequency masks nearby tones much more than distant ones; Masking acts within critical bandwidths, leaving distant-frequency sounds unaffected — Eric J. Heller, Why You Hear What You Hear- An…, 2009; High- and low-side suppression rest on different cochlear mechanisms — Dijk, Pim van, Physiology, Psychoacoustics and…, 3876 (+2 more)

Broader Connections

• Masking acts within critical bandwidths, leaving distant-frequency sounds unaffected #qualifies (0.85) — Eric J. Heller, Why You Hear What You Hear- An…, 2009
• Simultaneous tones become harder to perceive due to masking effects #exemplifies (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1628
• Higher auditory thresholds predict smaller low-side suppression only at high signal levels #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 949
• High- and low-side suppression rest on different cochlear mechanisms #complicates (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3876