A critical band is defined as?

• A. A frequency range processed together by the auditory system
• B. A single frequency processed independently
• C. A range of frequencies perceived as distinct tones
• D. The bandwidth of the cochlea

Answer: (A)

The central idea here is how the ear groups nearby frequencies into perceptual channels. A critical band is the range of frequencies that are processed together by the same auditory filter in the auditory system. When components fall within this band, they interact and tend to mask one another, making it hard to hear them as separate tones. If a spectral component lies outside the band, it is more likely to be processed by a different filter, so it can be heard as a distinct tone.

So, the correct description is that a critical band is a frequency range processed together by the auditory system. The other statements don’t fit because a critical band isn’t about a single frequency in isolation, nor about a range being heard as distinct tones within the same band, and it isn’t simply the physical bandwidth of the cochlea but rather the functional bandwidth of auditory filters that governs masking and fusion of tones.