Most comfortable listening for the loudness and intelligibility of speech.

The effect of instructional set upon most comfortable listening (MCL) was investigated among normal listeners. MCL level and range were determined (method of limits) in relation to listening for comfortable speech loudness versus comfortable speech intelligibility. The results indicate that instructional set does influence listener performance. the mean MCL level for comfortable speech intelligibility was significantly higher (4.96 dB) than the mean level for comfortable speech loudness; the mean MCL range for comfortable speech intelligibility was higher by 7.33 dB and wider by 7.10 dB than the mean range for speech loudness. Ascending stimulus presentation obtained comparable MCL levels for both listening conditions, whereas descending presentation obtained a mean MCL level almost 10 dB higher for comfortable speech intelligibility than for comfortable speech loudness. Males achieved slightly higher MCL levels than did females for both loudness (4.32 dB) and intelligibility (4.96 dB) criteria. It was concluded that the nature of the instructional set be taken into account when interpreting comfortable listening measures.