Professional and amateur bass/baritone singers with experience both as soloists and choir singers heard their own voice mixed with a piano accompaniment while they performed a specially composed solo selection. Then the piano accompaniment was replaced by a recording of a choir made in the bass section during rehearsal and the subjects were asked to sing the bass part. In each case the subject's voices were recorded, and comparisons were made between similar vowels sung at the same pitch and sound pressure level. The output spectra are noticeably greater in the region of the singer's formant [J. Sundberg, J. Acoust. Soc. Am.55,838 (1977)] in the solo singing mode. However, differences in the source spectra, obtained by inverse filtering of the formants, are not consistent among the singer subjects.