Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

Abstract

Normal-hearing (NH) listeners and hearing-impaired (HI) listeners detected and discriminated timereversed harmonic complexes constructed of equalamplitude harmonic components with fundamental frequencies (F0s) ranging from 50 to 800 Hz. Component starting phases were selected according to the positive and negative Schroeder-phase algorithms to produce within-period frequency sweeps with relatively flat temporal envelopes. Detection thresholds were not affected by component starting phases for either group of listeners. At presentation levels of 80 dB SPL, NH listeners could discriminate the two waveforms nearly perfectly when the F0s were less than 300-400 Hz but fell to chance performance for higher F0s. HI listeners performed significantly poorer, with reduced discrimination at several of the F0s. In contrast, at a lower presentation level meant to nearly equate sensation levels for the two groups, NH listeners' discrimination was poorer than HI listeners at most F0s. Roving presentation levels had little effect on performance by NH listeners but reduced performance by HI listeners. The differential impact of roving level suggests a weaker perception of timbre differences and a greater susceptibility to the detrimental effects of experimental uncertainty in HI listeners.

Neural processing and perception of Schroeder‐phase harmonic tone complexes in the gerbil: Relating single‐unit neurophysiology to behavior

“…A GLMM ANOVA with data from both species and the same parameters as for the ANOVA above showed that the sensitivity for discriminating sweep direction in humans was significantly higher than in gerbils ( p < 0.001). These results were generally consistent with previously reported results in human listeners (e.g., Drennan et al, 2008; Lauer et al, 2009). Note that the human testing was only carried out for the sweep‐direction experiment, which had fewer test conditions than the sweep‐velocity experiment and for which comparison data were available (Dooling et al, 2002).…”

Spectral and Temporal Measures in Hybrid Cochlear Implant Users

“…Published performance data from nonimplanted hearing impaired and normal subjects on the Schroeder-phase discrimination 21 and temporal modulation detection 20 tests were employed for comparison purposes. Details appear in the referenced publications.…”

“…Previously published hearing impaired and normal data are displayed for reference. 21 (EA, electroacoustic, HI, hearing impaired; error bars are SEM)…”

Psychoacoustic Performance and Music and Speech Perception in Prelingually Deafened Children with Cochlear Implants

“…Positive and negative Schroeder-phase stimuli have nearly flat temporal envelopes and identical long-term spectra but a different temporal fine structure [Schroeder, 1970]. Thus, Schroeder-phase discrimination has been used to evaluate the acoustic temporal fine structure sensitivity in normal-hearing and hearing-impaired listeners [Summers and Leek, 1998;Summers, 2000;Oxenham and Dau, 2001;Dooling et al, 2002;Lauer et al, 2009]. demonstrated that Schroeder-phase discrimination evaluates the ability of CI users to track temporal modulations that sweep rapidly across channels.…”