Speaker’s comfort and vocal effort in different room acoustic conditions: A controlled field experiment in a university lecture room

Speaking in poor acoustic conditions constitutes a risk factor for voice disorders. This study investigated how speaker’s comfort and vocal effort were affected during short speech tasks in four different room acoustic configurations. Voice recordings of the speech tasks and self-evaluations of the speaker’s comfort were collected from 15 participants in four room acoustic configurations as part of an acoustic refurbishment in a university lecture room. The influence of background babble noise and the use of a classroom sound field amplification system were also investigated. Results indicate that speaker’s comfort increased, and vocal effort decreased post-refurbishment, in configurations with reflectors or diffusers above the speaker position. Further, speaker’s comfort decreased, and vocal SPL and f_oincreased, indicating higher vocal effort, in conditions with background noise. Sex differences were observed both regarding vocal effort and speaker’s comfort in noisy conditions. Our results suggest that reflective materials above the speaker position, which enable more early reflections, are important for improving speaker’s comfort.