The cognitive effort associated with speaking clearly in noise: A pilot study

Abstract

Individuals with voice and speech disorders often struggle to implement therapy techniques in real-world environments. Background noise is a known distractor that deteriorates performance in cognitive and non-speech motor tasks. The noise may disturb talkers in a similar manner; however, its effect has been poorly described. This study evaluated the effect of background noise on talkers’ ability to maintain clear speech, a well-documented intelligibility enhancement technique, and corresponding cognitive effort. Participants of the study were 10 native English speakers who have no history of voice and speech disorders. The participants were asked to read sentences and describe pictures in habitual speech and clear speech within two noise environments: quiet and two-talker babble noise. The participants rated their perceived level of overall effort, mental effort, physical effort, frustration, and performance using a modified NASA-TLX scale for each noise condition. The degree of cognitive effort during the tasks was also measured by pupillometry. Their voice recordings were acoustically analyzed for intensity, spectral slope, and speech rate. Preliminary findings indicate that (1) production of clear speech requires greater cognitive effort, especially in noise, and (2) the degree of agreement between the subjective rating and physical measurement of mental effort varies across the talkers.