Masking-Level Difference in Filtered-Random and Amplitude-Modulated Noise

1984 ◽  
Vol 27 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Richard H. Wilson ◽  
John T. Argos ◽  
Carolyn J. Brown ◽  
Leslie A. Bennett
Keyword(s):  
Power Spectrum ◽  
Random Noise ◽  
Spectrum Level ◽  
Zero Crossings ◽  
Level Difference ◽  
Masking Level Difference ◽  
Filtered Noise

The masking characteristics of filtered-random noise and amplitude-modulated noise (40-dB pressure-spectrum level) were studied in a series of four experiments using a masking-level difference paradigm, that is, 500-Hz thresholds in S o N o and S π N o binaural conditions. In Experiment 1 a filtered noise (200–800 Hz) and an amplitude-modulated noise (425–575 Hz) produced equal thresholds in S o N o ; for S π N o , however, the thresholds in amplitude-modulated noise were 1.6 dB lower than were the thresholds in filtered noise. In Experiment 2 S o N o and S π N 0 thresholds were established in three filtered noise bandwidths (200–800 Hz, 335–685 Hz, and 410–600 Hz) and in the amplitude-modulated noise (425–575 Hz). When the bandwidths of the filteredrandom and amplitude-modulated noises were similar, the SπN o thresholds were the same but the S o N o thresholds were different. Experiments 3 and 4 indicated that with amplitude-modulated noise when the zero amplitude crossings of the tone and the noisecoincided, the S o N o , SπN o , and S m N m thresholds were 1.2–2.0 dB higher than were the thresholds when the zero crossings of the tone and noise did not coincide. The data indicate that the masking characteristics of filtered-random noise and amplitudemodulated noise are different. The findings are interpreted as an indication that perceptual phenomena depend on the temporal characteristies as well as the power spectrum of the signal and masker.

Masking release for gap detection

1992 ◽  
Vol 336 (1278) ◽  
pp. 331-337 ◽  
Keyword(s):  
Random Noise ◽  
Detection Threshold ◽  
Signal Frequency ◽  
Frequency Noise ◽  
Gap Detection ◽  
Noise Masking ◽  
Level Difference ◽  
Masking Release ◽  
Masking Level Difference ◽  
Release From Masking

In random noise, masking is influenced almost entirely by noise components in a narrow band around the signal frequency. However, when the noise is not random, but has a modulation pattern which is coherent across frequency, noise components relatively remote from the signal frequency can actually produce a release from masking. This masking release has been called comodulation masking release (CMR). The present research investigated whether a similar release from masking occurs in the analysis of a suprathreshold signal. Specifically, the ability to detect the presence of a temporal gap was investigated in conditions which do and do not result in CMR for detection threshold. Similar conditions were investigated for the masking level difference (a binaural masking release phenomenon). The results indicated that suprathreshold masking release for gap detection occurred for both the masking-level difference (MLD) and for CMR. However, masking release for gap detection was generally smaller than that obtained for detection threshold. The largest gap detection masking release effects obtained corresponded to relatively low levels of stimulation, where gap detection was relatively poor.

Influence of Signal Duration on the Masking-Level Difference

1987 ◽  
Vol 30 (3) ◽  
pp. 330-334 ◽  
Author(s):  
Richard H. Wilson ◽  
Ruth A. Fugleberg
Keyword(s):  
Forced Choice ◽  
Broadband Noise ◽  
Signal Duration ◽  
Spectrum Level ◽  
Level Difference ◽  
Masking Level Difference ◽  
Choice Method

The effect of signal duration on the 500-Hz masking-level difference was studied in 4 subjects using an adaptive, two-interval, forced-choice method. S o N o , S π N o , and S o N π thresholds for 13 signal durations between 2 and 100 ms were established incontinuous broadband noise (36.2 dB pressure-spectrum level). The signals were synthesized and gated digitally with 1-ms rise-fall times. The S o N o threshold integration functions diverged from the S π N o or the S o N π threshold integration functions as the signal duration was reduced from 100 ms to 6–10 ms. As the signal duration was reduced below 6–10 ms, however, the threshold integration functions for S o N o , S π N o , and S o N π converged. The relationships among the threshold integration functions were reflected in the S o N o -S π N o and the S o N o -S o N π masking-level differences that increased as the signal duration was reduced from 100 to 6–10 ms and then decreased as the signal duration was reduced below 6–10 ms.

Development of a 500-Hz Masking-Level Difference Protocol for Clinic Use

2003 ◽  
Vol 14 (01) ◽  
pp. 001-008 ◽  
Author(s):  
Richard H. Wilson ◽  
Deborah W. Moncrieff ◽  
Elizabeth A. Townsend ◽  
Amanda L. Pillion
Keyword(s):  
Normal Hearing ◽  
Signal To Noise ◽  
Spectrum Level ◽  
Level Difference ◽  
Masking Level Difference ◽  
Single Interval ◽  
Series Of Experiments ◽  
The Mean ◽  
Perceptual Abilities ◽  
Response Task

The purpose of this series of experiments was to develop a simple, 500-Hz masking-level difference (MLD) protocol that could be implemented easily in the clinic to assess auditory perceptual abilities using an audio compact disc. Five, 300-ms tones with 250-ms intertone intervals were embedded in 3-s bursts of 200-800 Hz noise presented at 42.2-dB pressure-spectrum level with 4-5 s inter-stimulus intervals. The homophasic and antiphasic conditions were interleaved with the signal-to-noise ratios decreasing in 2-dB steps. A single-interval, "yes/no" response task was used. Three experiments were performed on 24-28 listeners with normal hearing. The mean SoNo thresholds (58.1- to 59.5-dB SPL) and the mean SπNo thresholds (45.1- to 46.0-dB SPL) produced ˜13-dB MLDs. Experiment 3 included a SoNπ condition that had a mean threshold of 48.8-dB SPL and a 10.0-dB MLD. The mean test, retest ot the SoNo and SπNo thresholds on 15 listeners was <0.5 dB. Over the three experiments, 95% of the listeners had SπNo MLDs that were ≥10 dB.

scholarly journals Sufficiency of a Gaussian power spectrum likelihood for accurate cosmology from upcoming weak lensing surveys

2021 ◽  
Author(s):  
Robin E Upham ◽  
Michael L Brown ◽  
Lee Whittaker
Keyword(s):  
Power Spectrum ◽  
Random Noise ◽  
Power Spectra ◽  
Stage Iv ◽  
Wishart Distribution ◽  
Weak Lensing ◽  
Dependence Structure ◽  
Gaussian Fields ◽  
Non Gaussian ◽  
Parameter Constraints

Abstract We investigate whether a Gaussian likelihood is sufficient to obtain accurate parameter constraints from a Euclid-like combined tomographic power spectrum analysis of weak lensing, galaxy clustering and their cross-correlation. Testing its performance on the full sky against the Wishart distribution, which is the exact likelihood under the assumption of Gaussian fields, we find that the Gaussian likelihood returns accurate parameter constraints. This accuracy is robust to the choices made in the likelihood analysis, including the choice of fiducial cosmology, the range of scales included, and the random noise level. We extend our results to the cut sky by evaluating the additional non-Gaussianity of the joint cut-sky likelihood in both its marginal distributions and dependence structure. We find that the cut-sky likelihood is more non-Gaussian than the full-sky likelihood, but at a level insufficient to introduce significant inaccuracy into parameter constraints obtained using the Gaussian likelihood. Our results should not be affected by the assumption of Gaussian fields, as this approximation only becomes inaccurate on small scales, which in turn corresponds to the limit in which any non-Gaussianity of the likelihood becomes negligible. We nevertheless compare against N-body weak lensing simulations and find no evidence of significant additional non-Gaussianity in the likelihood. Our results indicate that a Gaussian likelihood will be sufficient for robust parameter constraints with power spectra from Stage IV weak lensing surveys.

The effect of diotic and dichotic level-randomization on the binaural masking-level difference

2005 ◽  
Vol 118 (5) ◽  
pp. 3229-3240 ◽  
Author(s):  
G. Bruce Henning ◽  
Virginia M. Richards ◽  
Jennifer J. Lentz
Keyword(s):  
Level Difference ◽  
Masking Level Difference

scholarly journals Masking Level Difference and Electrophysiological Evaluation in Adults with Normal Hearing

2020 ◽  
Vol 24 (04) ◽  
pp. e399-e406
Author(s):  
Joyce Miranda Santiago ◽  
Cyntia Barbosa Laureano Luiz ◽  
Michele Garcia ◽  
Daniela Gil
Keyword(s):  
Auditory Processing ◽  
Auditory Evoked Potentials ◽  
Normal Hearing ◽  
Central Auditory Processing ◽  
Positive Correlation ◽  
Binaural Interaction ◽  
Level Difference ◽  
Significant Difference ◽  
Masking Level Difference ◽  
The Mean

Abstract Introduction The auditory structures of the brainstem are involved in binaural interaction, which contributes to sound location and auditory figure-background perception. Objective To investigate the performance of young adults in the masking level difference (MLD) test, brainstem auditory-evoked potentials (BAEPs) with click stimulus, and frequency-following response (FFR), as well as to verify the correlation between the findings, considering the topographic origin of the components of these procedures. Methods A total of 20 female subjects between 18 and 30 years of age, with normal hearing and no complaints concerning central auditory processing underwent a basic audiological evaluation, as well as the MLD test, BAEP and FFR. Results The mean result on the MLD test was of 10.70 dB. There was a statistically significant difference in the absolute latencies of waves I, III and V in the BAEPs of the ears. A change in the FFR characterized by the absence of the C, E and F waves was noticed. There was a statistically significant difference in the positive correlation of wave V in the BAEPs with the MLD. There was a statistically significant difference in the positive correlation of the mean MLD and the V, A and F components of the FFR. Conclusion The mean MLD was adequate. In the BAEPs, we observed that the click stimulus transmission occurred faster in the right ear. The FFR showed absence of some components. The mean MLD correlated positively with the BAEPs and FFR.

A masking‐level difference in time (MLDT)

1982 ◽  
Vol 71 (S1) ◽  
pp. S37-S37
Author(s):  
Roy D. Patterson ◽  
Robert Milroy
Keyword(s):  
Level Difference ◽  
Masking Level Difference
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