title: Effects of differences in fundamental frequency on across-formant grouping in speech perception.
abstract: In an isolated syllable, a formant will tend to be segregated perceptually if its fundamental frequency (F0) differs from that of the other formants. This study explored whether similar results are found for sentences, and specifically whether differences in F0 (ΔF0) also influence across-formant grouping in circumstances where the exclusion or inclusion of the manipulated formant critically determines speech intelligibility. Three-formant (F1 + F2 + F3) analogues of almost continuously voiced natural sentences were synthesized using a monotonous glottal source (F0 = 150 Hz). Perceptual organization was probed by presenting stimuli dichotically (F1 + F2C + F3; F2), where F2C is a competitor for F2 that listeners must resist to optimize recognition. Competitors were created using time-reversed frequency and amplitude contours of F2, and F0 was manipulated (ΔF0 = ± 8, ± 2, or 0 semitones relative to the other formants). Adding F2C typically reduced intelligibility, and this reduction was greatest when ΔF0 = 0. There was an additional effect of absolute F0 for F2C, such that competitor efficacy was greater for higher F0s. However, competitor efficacy was not due to energetic masking of F3 by F2C. The results are consistent with the proposal that a grouping "primitive" based on common F0 influences the fusion and segregation of concurrent formants in sentence perception.
authors.affiliation: School of Life and Health Sciences, Aston University, Birmingham B4 7ET, United Kingdom.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Summers
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Bailey
authors.forename: Brian
authors.initials: B
authors.lastname: Roberts
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001306:Auditory Pathways / Q000502:physiology*; D001309:Auditory Threshold; D032882:Comprehension; D004007:Dichotic Listening Tests; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010470:Perceptual Masking; D010898:Pitch Perception; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors; D055815:Young Adult