title: Hearing sensitivity to shifts of rippled-spectrum patterns.
abstract: The sensitivity of human hearing to shifts in rippled spectrum patterns of sound was investigated. The test signal was band-limited rippled noise with spectrum ripples of various frequency spacing and bandwidth; this type of sound may be considered as a quantitatively controlled imitation of complex natural sounds. The listener was required to detect a shift in the spectrum ripple phase while keeping the other parameters of the noise constant. For cosine-shaped ripples, the lowest threshold (1.1%) was found at a ripple frequency of 3.5 ripples per octave (rpo), which corresponds to a ripple spacing of 20% of the center frequency. The threshold increased for both lower and higher ripple densities. Qualitatively similar patterns of threshold dependence on ripple density were observed for center frequencies from 1 to 4 kHz. Making the ripples narrower than cosine decreased the thresholds to 0.7%-0.75% for ripple densities of 2-5 rpo. Keeping the ripple width constant at 3.5%-7.5% of the frequency resulted in a monotonic threshold dependence on ripple density: The threshold decreased with decreasing density (down to 0.7%). An excitation-pattern model explains qualitatively the observed dependence of the ripple-phase shift threshold on ripple pattern parameters.
authors.affiliation: Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninsky Prospect, 119071 Moscow, Russia.
authors.forename: Dmitry I
authors.initials: DI
authors.lastname: Nechaev
authors.forename: Alexander Ya
authors.initials: AY
authors.lastname: Supin
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D001299:Audiometry; D001306:Auditory Pathways / Q000502:physiology*; D001309:Auditory Threshold; D006309:Hearing; D006801:Humans; D008875:Middle Aged; D008960:Models, Psychological; D046709:Pattern Recognition, Physiological; D010898:Pitch Perception; D011571:Psychoacoustics; D017603:Signal Detection, Psychological; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult