Cookie Bite Hearing Loss
Cookie bite hearing loss, also called mid-frequency hearing loss or a U-shaped audiogram, is a configuration in which hearing thresholds are relatively better at both low and high frequencies but significantly reduced in the mid-frequency range, roughly 1,000 to 2,000 Hz. When plotted on an audiogram, the resulting curve dips in the middle and rises at both ends, resembling a bite taken from the middle of a cookie.
This pattern is less common than high-frequency or flat hearing loss. It is most often associated with genetic or hereditary causes, though it can also arise from autoimmune inner ear disease or, in some cases, Meniere's disease. The mid-frequency range is important for speech intelligibility because it contains many of the resonances and formants that distinguish vowel sounds from one another. People with cookie bite hearing loss may have particular difficulty understanding speech at normal conversational volumes, even though they may hear very soft and very loud sounds.
Hearing aid programming for this configuration requires a distinct approach, amplifying the mid-frequency range while avoiding over-amplification of the frequencies where hearing is relatively intact. Genetic counseling may be relevant when a familial pattern is identified.
