Conductive hearing loss can be modeled as a filter, but sensorineural loss cannot

Evidence

The outer and middle ears have transfer functions that are band-pass in nature. Although these systems serve to amplify sound, they do so in a way that amplifies the mid-frequencies more than higher or lower frequencies. In some cases, hearing loss can often be described using a filter transfer function: a conductive low-frequency hearing loss, for example, can be modeled as a high-pass filter. The filter analogy is extremely appropriate for conductive losses, as conductive losses tend to simply attenuate sound and do not contribute to additional perceptual distortions. On the other hand, it might seem appropriate to describe a sloping sensorineural hearing loss as a low-pass filter, due to the greater attenuation of high frequencies compared with the low frequencies. However, the distortions and perceptual deficits that accompany sensorineural hearing loss prevent the filter analogy from being wholly suitable. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 430

Categorization

• DEFINE: Clarifies how filter transfer functions describe ear and hearing-loss behavior, distinguishing conductive from sensorineural cases.
• XREF: Connects to sensorineural distortions discussed throughout the rest of the book; reader building a normal-vs-impaired model needs this framework.