Narrow-band devices like telephones degrade temporal cue coding and raise listening effort

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

• SHARE: Sensorineural-loss and audiology insight — worth sending to someone applying hearing-aid fitting or telephone bandwidth issues; the 6000 vs 8000 vs 14000 Hz contrast is a precise clinical hook.
• XREF: Connects to listening-effort literature and to why hearing aids with limited bandwidth may impair temporal resolution even when speech intelligibility looks intact.
• SEED: Article angle: ‘decoding effort’ as an invisible cost of bandwidth-limited devices — the listening gets done, but at extra cognitive price the user pays silently.