What function does a TILL circuit serve in hearing aids?

The function of a TILL circuit in hearing aids primarily focuses on enhancing high frequencies in specific listening environments, particularly those that are quiet. This enhancement is crucial for individuals with hearing loss, as they often have difficulty perceiving higher frequency sounds, such as speech consonants, which are important for clarity in communication. By boosting these frequencies in quiet settings, the TILL circuit helps users better understand speech and environmental sounds, ultimately improving their listening experience.

In contrast, other options may address different aspects of sound processing that are not aligned with the specific role of a TILL circuit in enhancing high frequencies.