title: Discrimination of rippled-spectrum patterns in noise: A manifestation of compressive nonlinearity.
abstract: In normal-hearing listeners, rippled-spectrum discrimination was psychophysically investigated in both silence and with a simultaneous masker background using the following two paradigms: measuring the ripple density resolution with the phase-reversal test and measuring the ripple-shift threshold with the ripple-shift test. The 0.5-oct wide signal was centered on 2 kHz, the signal levels were 50 and 80 dB SPL, and the masker levels varied from 30 to 100 dB SPL. The baseline ripple density resolutions were 8.7 oct-1 and 8.6 oct-1 for the 50-dB and 80-dB signals, respectively. The baseline ripple shift thresholds were 0.015 oct and 0.018 oct for the 50-dB and 80-dB signals, respectively. The maskers were 0.5-oct noises centered on 2 kHz (on-frequency) or 0.75 to 1.25 oct below the signal (off-frequency maskers). The effects of the maskers were as follows: (i) both on- and low-frequency maskers reduced the ripple density resolution and increased the ripple shift thresholds, (ii) the masker levels at threshold (the ripple density resolution decrease down to 3 oct-1 or ripple shift threshold increased up to 0.1 oct) increased with increasing frequency spacing between the signal and masker, (iii) the masker levels at threshold were higher for the 80-dB signal than for the 50-dB signal, and (iv) the difference between the masker levels at threshold for the 50-dB and 80-dB signals decreased with increasing frequency spacing between the masker and signal. Within the 30-dB (from 50 to 80 dB SPL) signal level, the growth of the masker level at threshold was 27.8 dB for the on-frequency masker and 9 dB for the low-frequency masker. It is assumed that the difference between the on- and low-frequency masking of the rippled-spectrum discrimination reflects the cochlear compressive non-linearity. With this assumption, the compression was 0.3 dB/dB.
authors.affiliation: Institute of Ecology and Evolution, Russian Academy of Sciences. 33 Leninsky Prospect, Moscow, Russia.
authors.forename: Olga N
authors.initials: ON
authors.lastname: Milekhina
authors.affiliation: Institute of Ecology and Evolution, Russian Academy of Sciences. 33 Leninsky Prospect, Moscow, Russia.
authors.forename: Dmitry I
authors.initials: DI
authors.lastname: Nechaev
authors.affiliation: Institute of Ecology and Evolution, Russian Academy of Sciences. 33 Leninsky Prospect, Moscow, Russia.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Klishin
authors.affiliation: Institute of Ecology and Evolution, Russian Academy of Sciences. 33 Leninsky Prospect, Moscow, Russia.
authors.forename: Alexander Ya
authors.identifier: http://orcid.org/0000-0002-3609-2766
authors.initials: AY
authors.lastname: Supin
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D010470:Perceptual Masking / Q000502:physiology; D011571:Psychoacoustics; D055815:Young Adult