title: Perceptual evaluations of voice scatter in unison choir sounds.
abstract: The preferences of experiences listerners for pitch and formant frequency dispersion in unison choir sounds were explored using synthesized stimuli. Two types of dispersion were investigated: (a) pitch scatter, which arises when voices in an ensemble exhibit small differences in mean fundamental frequency, and (b) spectral smear, defined as such dispersion of formants 3 to 5 as arises from differences in vocal tract length. Each stimulus represented a choir section of five bass, tenor, alto, or soprano voices, producing the vowel [u], [a], or [ae]. Subjects chose one dispersion level out of six available, selecting the "maximum tolerable" in a first run and the "preferred" in a second run. The listeners were very different in their tolerance for dispersion. Typical scatter choices were 14 cent standard deviation for "tolerable" and 0 or 5 cent for "preferred." The smear choices were less consistent; the standard deviations were 12 and 7%, respectively. In all modes of assessment, the largest dispersion was chosen for the vowel [u] on a bass tone. There was a vowel effect on the smear choices. The effects of voice category were not significant.
authors.affiliation: Department of Speech Communication and Music Acoustics, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Ternström
mesh_terms: D005260:Female; D006801:Humans; D007830:Larynx / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D010699:Phonation / Q000502:physiology; D010700:Phonetics; D013061:Speech Acoustics; D014831:Voice / Q000502:physiology*; D014833:Voice Quality; D014834:Voice Training