Bandwidth-limiting devices degrade temporal coding even when speech remains intelligible

Evidence

The wider the stimulus bandwidth, the better the gap detection threshold. The auditory system is able to use information across a wide frequency range to gather information, even temporal information. We can infer from this result that providing access to stimuli with the widest bandwidth possible is important for robust coding of acoustic temporal information. Consider how the telephone, which only represents frequencies up to about 3500 Hz, or a hearing aid with a bandwidth of 6000 kHz, might impair the representation of temporal information present in speech, which has a bandwidth of closer to 8000 Hz, and music, having a bandwidth of 14,000 Hz. In both cases, a listener is in an impoverished auditory environment. By not having access to the full bandwidth of environmental stimuli, the ability to take advantage of broadband temporal changes may be impacted in a negative way. Note that we may not notice a large decrease in speech understanding, but decoding the information in the impoverished speech signal may require more effort on the part of the listener. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 990

Categorization

Category: Factual Claims

• XREF: Direct audiology application: hearing aids and telephony cap bandwidth (~3500 Hz / 6000 Hz) versus speech’s 8000 Hz and music’s 14000 Hz; connects to the ‘grafting and growth’ infrastructure lens — hearing is about built environmental access.
• SEED: Essay angle: the hidden cognitive effort cost of bandwidth-limited audio — speech may stay intelligible while decoding effort rises, a hearing-infrastructure version of ‘impoverished environments.‘

Related

• Narrow-band devices like telephones degrade temporal cue coding and raise listening effort (similarity 0.93)
• Wide bandwidth improves temporal perception while low-pass filtering limits it (similarity 0.87)
• Wider stimulus bandwidth improves the ear’s temporal acuity (similarity 0.83)
• Wider stimulus bandwidths improve listeners’ ability to detect temporal gaps (similarity 0.81)
• Hearing loss reduces audibility and restricts usable bandwidth for temporal processing (similarity 0.80)
• Hearing aids address three deficits but leave frequency, temporal, and pitch processing unaddressed. (similarity 0.79)
• The auditory system’s ~120 dB dynamic range exceeds any single nerve fiber’s coding capacity (similarity 0.79)
• Audibility is the greatest factor in hearing-loss communication difficulty (similarity 0.78)