The Acclimatization Effects of Earplugs on Acoustic and Perceptual Measures of University Singers' Vocal Performances in Choral and Solo Settings

Abstract

ABSTRACT The purpose of this study was to assess with female university singers (N = 34) the potential acclimatization effects of wearing one brand of earplugs marketed to musicians on selected acoustic and perceptual measures of choral and vocal sound. Data were acquired during four data collection sessions across four weeks. Participants were members of two established women's choirs, Group A (n = 24) and Group B (n = 10). Each choir sang the same musical excerpt three times during weekly data collection periods: without-earplugs at rehearsal start, with-earplugs at rehearsal start, and with-earplugs at rehearsal end. For comparison purposes, Group A wore the earplugs at each of three rehearsals per week, while Group B wore the earplugs only during data collection rehearsals. Additionally, one-half of the singers, randomly selected, participated in weekly solo recording sessions that followed a similar protocol. Digital audio recordings of the choral and solo singing performances were used for analyses of long term average spectra (LTAS), intonation, and amplitude. Among primary results: (a) choral and solo LTAS data indicated significant differences in mean signal amplitudes between the no-earplugs and with-earplugs conditions, (b) solo amplitude means indicated a < 1 dB difference between conditions in 90% of the recordings, (c) choral pitch analyses indicated earplugs did not cause choristers to sing less in-tune, (d) fundamental frequency analyses indicated that earplugs did not cause soloists to sing significantly more or less in-tune, and (e) the majority of choral (87.50%) and solo singers (75%) reported being able to hear themselves best when not wearing earplugs during the weekly recording sessions. The results were discussed in terms of possible acclimatization effects, limitations of the study, and suggestions for future research.