The effect of noise fluctuation and spectral bandwidth on gap detection

Abstract

Experiment 1 investigated gap detection for random and low-fluctuation noise (LFN) markers as a function of bandwidth (25-1600 Hz), level [40 or 75 dB sound pressure level (SPL)], and center frequency (500-4000 Hz). Gap thresholds for random noise improved as bandwidth increased from 25 to 1600 Hz, but there were only minor effects related to center frequency and level. For narrow bandwidths, thresholds were lower for LFN than random markers; this difference extended to higher bandwidths at the higher center frequencies and was particularly large at high stimulus level. Effects of frequency and level were broadly consistent with the idea that peripheral filtering can increase fluctuation in the encoded LFN stimulus. Experiment 2 tested gap detection for 200-Hzwide noise bands centered on 2000 Hz, using high-pass maskers to examine spread of excitation effects. Such effects were absent or minor for random noise markers and the 40-dB-SPL LFN markers. In contrast, some high-pass maskers substantially worsened performance for the 75-dB-SPL LFN markers. These results were consistent with an interpretation that relatively acute gap detection for the high-level LFN gap markers resulted from spread of excitation to higherfrequency auditory filters where the magnitude and phase characteristics of the LFN stimuli are better preserved.

Auditory temporal resolution in adaptive tasks

“…The aim of the study was to explore the clinical utility of the Windows-based psychoacoustic experimental software Psycon (Version 2.18) and to estimate GDTs and to provide normative values for young listeners in the BBN, NBN WC, and NBN AC conditions. The overall results obtained with the above detailed parameters were consistent with those of previous study that used a similar methodology 7-9,11,14,21,23-25…”

Gap Detection in School-Age Children and Adults: Center Frequency and Ramp Duration

“…That study also reported that adults' thresholds were consistently approximately 20 ms for 25-Hzwide bands of low-fluctuation noise centered on 500, 1000, 2000, or 4000 Hz. One difference between the stimuli used by Hall et al (2016) and those of the present study is that stimuli in the previous study were gated on during each listening interval rather than playing continuously, as in the present study. Continuous presentation has been observed to cause loudness adaptation, particularly at high stimulus frequencies (Hellman, Miskiewicz, & Scharf, 1997;Miskiewicz, Scharf, Hellman, & Meiselman, 1993).…”

“…The relatively wide auditory filter at 5000 Hz may preserve these characteristics better than the narrower filter at 500 Hz. Hall, Buss, Ozmeral, and Grose (2016) recently provided some evidence that auditory filtering affects the internal representation of low-fluctuation noise, albeit for bandwidths wider than 25 Hz. That study also reported that adults' thresholds were consistently approximately 20 ms for 25-Hzwide bands of low-fluctuation noise centered on 500, 1000, 2000, or 4000 Hz.…”