Loudness recruitment in impaired listeners could reveal how cortex encodes perceived level

Evidence

The largely linear relationship between categorical loudness and sound intensity over the range of presented levels, as well as the fact that our participants were from a rather homogenous group of normal hearing listeners with similar loudness perception, might have limited the ability to differentiate between the contributions of both measures to neural activation in the human auditory system. A promising next step would be the inclusion of hearing impaired participants characterized by an altered relationship between sound intensity and perceived loudness (e.g., loudness recruitment). Moreover, this approach could provide additional valuable information about the nature of hearing disorders associated with distorted loudness perceptions. This in the end might open a potential for the diagnostic use of auditory fMRI. Although it is yet to prove how well the present findings pertain to the hearing impaired listeners, our results so far point towards the activation of the posterior medial section of Heschl’s gyrus as the most reliable indicator of individually perceived loudness. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2647

Categorization

• SEED: An essay or research thread on whether loudness recruitment normalizes or distorts cortical coding of subjective level — comparing normal vs recruiting ears could separate physical from perceptual encoding.