What type of distortion occurs when sound leaving the hearing aid differs in its frequency spectrum from the input signal?

Frequency distortion occurs when the frequency spectrum of the sound produced by the hearing aid does not match that of the original input signal. This type of distortion can result from changes in frequency response as the signal is processed, leading to some frequencies being amplified more than others, or some frequencies being attenuated. This mismatch can significantly affect sound quality, making it difficult for users to perceive sounds accurately, particularly in complex auditory environments.

Understanding frequency distortion is vital for hearing aid dispensers, as they must ensure that devices provide accurate amplification across the frequency range to which a user is most sensitive. This also highlights the importance of fine-tuning and calibrating hearing aids properly to minimize distortions and enhance the listening experience for users.