The Lombard effect in choral singing.

Selected vocal-intensity response-level readings of singers' ability to resist the Lombard effect in choral singing before and after verbal instructions were compared. Twenty-seven adults sang The Star Spangled Banner along with a choir heard through headphones. After instructions to resist increasing vocal intensity as the choir increased, each subject sang again. The performances were recorded, and vocal-intensity readings from selected places in the song were obtained from a graphic-level recorder. A 3 x 3 x 2 multiple analysis of variance procedure was performed on the scores; the main factors tested were experience level, pretest-posttest differences, and places in the song. No significant difference (0.05 level) for levels of experience was observed, but the effect of the instructions was significant (p < 0.05), suggesting that choral singers can learn to resist the Lombard effect and consciously regulate their vocal intensity to some extent in the face of masking sound.