Acoustical Analyses of Conversations Reveal Different Effects of Remote Microphones and Face Masks on Group...

This study investigated if changes in speech and conversation behavior by aided individuals with hearing loss could be observed across conditions with versus without the use of a remote microphone while wearing and not wearing a face mask.

Sixteen hearing aid users were randomly split into four groups of four. Each group engaged in a free-form conversation in the presence of a 55 dBA background noise in each of four conditions. The four conditions were based on combinations of two variables: with versus without a remote microphone and wearing versus not wearing a face mask. The recordings of the conversations were analyzed to compare measures of speech production and conversational behavior across conditions.

Conversations with a remote microphone exhibited shorter average floor transfer offsets (FTOs) and longer conversation durations. In conversations where masks were worn, the average fundamental frequency produced by talkers was lower. A complex interaction was observed in the influence of remote microphone and face mask on the average length of connected utterances.

Acoustic analysis of speech production and conversational behavior can be used to evaluate the benefit of hearing assistive technology. The observed differences in behavior when using a remote microphone are consistent with reduced listening effort. The differences observed when wearing a face mask are all consistent with increased resistance to airflow and the consequent effects on speech production rather than increased listening difficulty.