Single auditory neurons encode only a narrow 20-40 dB dynamic range
Evidence
The auditory nerve fibres show spontaneous firing even when no sound enters the ear. When the sound level is increased, the firing rate grows monotonically but starts to saturate above a specific level, as shown in Figure 7.16. The dynamic range is relatively narrow, about 20–40 dB for a single neuron (Moore, 2012). Auditory nerve fibres with a high spontaneous firing rate (about 20/s or more) are more sensitive but saturate first. The majority of neurons are of this type. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 785
Categorization
- QUESTION: How does the ear achieve its full ~120 dB dynamic range if single fibers only span 20-40 dB? Points to a rate-place/recruitment mechanism worth chasing.
- corroborated: 3 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 785
- XREF: connects to: The lower slope of auditory excitation patterns is constant at 27 dB per Bark; Individual auditory nerve fibers cannot code the full hearing dynamic range — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 240; Population coding across many neurons achieves precise and robust auditory processing — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 794 (+3 more)
Broader Connections
- Individual auditory nerve fibers cannot code the full hearing dynamic range
#corroborates(0.97) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 240 - Population coding across many neurons achieves precise and robust auditory processing
#expands(0.85) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 794 - Subcortical auditory structures encode sound intensity linearly while cortex compresses it.
#qualifies(0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 2645 - Faster-fluctuating sounds trigger less cochlear compression, trading sensitivity for better dynamic encoding
#complicates(0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3637