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🪵 The Threshold

Aging reduces envelope processing efficiency but not temporal resolution.

Properties2
tagsja-picks, xref, question, define, causal_relationships, trade, corroborated, category/factual-claims
aliases@van_dijk_physiology_2016, loc. 793

4 min read

Aging reduces envelope processing efficiency but not temporal resolution.

Evidence

Füllgrabe et al. ( 2015 ) also assessed sensitivity to ENV cues by measuring thresholds for detecting sinusoidal amplitude modulation imposed on a 4-kHz sinusoidal carrier. Modulation rates of 5, 30, 90, and 180 Hz were used to characterize the temporal-modulation-transfer function (TMTF). On average, thresholds (expressed as 20log10 m , where m is the modulation index) were 2–2.5 dB higher (worse) for the older than for the younger subjects. However, the shapes of the TMTFs were similar for the two groups. This suggests that increasing age is associated with reduced efficiency in processing ENV information, but not with reduced temporal resolution for ENV cues. — Dijk, Pim van, Physiology, Psychoacoustics and…, 793

Füllgrabe et al. ( 2015 ) also assessed sensitivity to ENV cues by measuring thresholds for detecting sinusoidal amplitude modulation imposed on a 4-kHz sinusoidal carrier. Modulation rates of 5, 30, 90, and 180 Hz were used to characterize the temporal-modulation-transfer function (TMTF). On average, thresholds (expressed as 20log10 m , where m is the modulation index) were 2–2.5 dB higher (worse) for the older than for the younger subjects. However, the shapes of the TMTFs were similar for the two groups. This suggests that increasing age is associated with reduced efficiency in processing ENV information, but not with reduced temporal resolution for ENV cues. Schoof and Rosen ( 2014 ) found no significant difference in either processing efficiency or the shape of TMTFs measured with noise-band carriers between young (19–29 years) and older (60–72 years) subjects with near-normal audiograms. It is possible that, with noiseband carriers, amplitude-modulation detection is limited by the inherent fluctuations in the carrier (Dau et al. 1997 ), making it hard to measure the effects of age. — Dijk, Pim van, Physiology, Psychoacoustics and…, 802

On average, thresholds (expressed as 20log10 m , where m is the modulation index) were 2–2.5 dB higher (worse) for the older than for the younger subjects. However, the shapes of the TMTFs were similar for the two groups. This suggests that increasing age is associated with reduced efficiency in processing ENV information, but not with reduced temporal resolution for ENV cues. — Dijk, Pim van, Physiology, Psychoacoustics and…, 796

On average, thresholds (expressed as 20log10 m , where m is the modulation index) were 2–2.5 dB higher (worse) for the older than for the younger subjects. However, the shapes of the TMTFs were similar for the two groups. This suggests that increasing age is associated with reduced efficiency in processing ENV information, but not with reduced temporal resolution for ENV cues. Schoof and Rosen ( 2014 ) found no significant difference in either processing efficiency or the shape of TMTFs measured with noise-band carriers between young (19–29 years) and older (60–72 years) subjects with near-normal audiograms. It is possible that, with noiseband carriers, amplitude-modulation detection is limited by the inherent fluctuations in the carrier (Dau et al. 1997 ), making it hard to measure the effects of age. — Dijk, Pim van, Physiology, Psychoacoustics and…, 802

Categorization

  • DEFINE: TMTF (temporal-modulation-transfer function) and the 20log10 m measure are introduced within a causal interpretation distinguishing efficiency from resolution.
  • QUESTION: The Schoof-and-Rosen null result with noise-band carriers suggests the carrier type itself masks age effects — worth comparing sinusoidal vs. noise carriers in future work.
  • XREF: Contrasts with the TFS aging result in location 801, showing aging affects two auditory cues differently. — connects to: Frequency selectivity, not temporal processing, drives age-related declines in Huggins-pitch thresholds.; Temporal-structure sensitivity declines with age even when audiograms remain normal. — Dijk, Pim van, Physiology, Psychoacoustics and…, 793; Aging degrades envelope-based binaural phase discrimination independent of hearing loss — Dijk, Pim van, Physiology, Psychoacoustics and…, 809 (+2 more)
  • corroborated: 6 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 793; Dijk, Pim van, Physiology, Psychoacoustics and…, 802; Dijk, Pim van, Physiology, Psychoacoustics and…, 796

Broader Connections

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