Binaural masking-level difference as a function of masker and test-signal duration

The ability to use binaural cues when stimulation was by bilaterally applied bone conduction (BC) transducers was investigated in 20 normal hearing participants. The results with BC stimulation were compared with normal air conduction (AC) stimulation through earphones. The binaural hearing ability was tested by spatial release from masking, binaural intelligibility level difference (BILD), binaural masking level difference (BMLD) using chirp stimulation, and test of the precedence effect. In all tests, the participants revealed a benefit of bilateral BC stimulation indicating use of binaural cues. In the speech based tests, the binaural benefit for BC stimulation was approximately half that with AC stimulation. For the BC BMLD test with chirp stimulation, there were indications of superposition of the ipsilateral and contralateral pathways at the cochlear level affecting the results. The precedence effect test indicated significantly worse results for BC stimulation than for AC stimulation with low-frequency stimulation while they were close for high-frequency stimulation; broad-band stimulation gave results that were slightly worse than the high-frequency results

Section: Binaural Masking Level Differencementioning

confidence: 73%

Section: Binaural Masking Level Differencementioning

confidence: 99%

Binaural hearing ability with mastoid applied bilateral bone conduction stimulation in normal hearing subjects

Stenfelt

Zeitooni

2013

“…This inverse relation between signal duration and binaural masked thresholds is indeed close to experimental data, which show an effect of 4.5 dB/doubling and 1.5 dB/doubling of signal duration for signal durations below and beyond 60 ms, respectively ͑cf. Zwicker and Zwicker, 1984;Yost, 1985;Wilson and Fowler, 1986;Wilson and Fugleberg, 1987͒. According to such a scheme, a doubling in masker duration while having a constant short signal duration should lead to a 3-dB increase in threshold.…”

Section: Motivation For Ei-based Binaural Processingmentioning

confidence: 96%

Binaural processing model based on contralateral inhibition. I. Model structure

Breebaart¹,

Par

Kohlrausch

2001

180

183

This article presents a quantitative binaural signal detection model which extends the monaural model described by Dau et al. [J. Acoust. Soc. Am. 99, 3615-3622 (1996)]. The model is divided into three stages. The first stage comprises peripheral preprocessing in the right and left monaural channels. The second stage is a binaural processor which produces a time-dependent internal representation of the binaurally presented stimuli. This stage is based on the Jeffress delay line extended with tapped attenuator lines. Through this extension, the internal representation codes both interaural time and intensity differences. In contrast to most present-day models, which are based on excitatory-excitatory interaction, the binaural interaction in the present model is based on contralateral inhibition of ipsilateral signals. The last stage, a central processor, extracts a decision variable that can be used to detect the presence of a signal in a detection task, but could also derive information about the position and the compactness of a sound source. In two accompanying articles, the model predictions are compared with data obtained with human observers in a great variety of experimental conditions.

“…The type of integration described above would be expected to produce the same magnitude of fringe effects independent of whether the fringe preceded or followed the signal. It is the case, however, that backward masking fringes yield enhancements of detectability for short-duration S signals masked by diotic broadband noise that are smaller than those observed for forward masking fringes ͑e.g., Trahiotis et al, 1972;Zwicker and Zwicker, 1984;Gilkey et al, 1990͒. Perhaps, the asymmetric fringe effects stem from differential "predetection" effects arising directly from the response of the peripheral auditory filters.…”

Section: The Forward Fringe Effectmentioning

confidence: 97%

Binaural detection of 500-Hz tones in broadband and in narrowband masking noise: Effects of signal/masker duration and forward masking fringes

Bernstein

Trahiotis

Freyman

2006

NoSpi thresholds for a 500-Hz tonal signal were measured with broadband and with narrowband maskers using a single-interval adaptive matrix procedure [C. Kaernbach, J Acoust. Soc. Am. 88, 2645-2655 (1990)]. The purpose of the study was to investigate and to account for the effects on thresholds of varying the durations of the signals and maskers and the durations of forward masking fringes that preceded the occurrence of signal-plus-noise. For detection in both broadband and narrowband noise, the addition of brief forward fringes of masking noise resulted in elevations in threshold for the shortest signal durations. Longer forward fringes led to larger decreases in threshold when the masker was broadband as compared to when the masker was narrowband. The complex patterning of the data was explained by the operation of: (1) "predetection" temporal integration associated with peripheral auditory filtering; (2) duration-dependent, across-frequency influences that differentially affect broadband and narrowband NoSpi thresholds, (3) "post-detection" temporal integration associated with the central binaural mechanism, and (4) consideration of the detection thresholds in terms of changes in interaural correlation rather than in terms of signal level or signal-to-noise ratio, per se.