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 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.

scholarly journals Evaluation of Binaural Interaction: Age-Related Altering Masking Level Difference in Normal Hearing Individuals

2021 ◽  
Vol 6 (3) ◽  
pp. 585-591
Author(s):  
Ahsen KARTAL ◽  
Barış YAMAN ◽  
Müjde KAYA ◽  
Burcu YERLİKAYA ◽  
Özlem KONUKSEVEN
Keyword(s):  
Normal Hearing ◽  
Binaural Interaction ◽  
Level Difference ◽  
Age Related ◽  
Masking Level Difference

Recognition Masking-Level Differences Spondaic Words for 10 Cid W-1

1982 ◽  
Vol 25 (4) ◽  
pp. 624-628 ◽  
Author(s):  
Richard H. Wilson ◽  
Janet E. Shanks ◽  
Katherine A. Koebsell
Keyword(s):  
Speech Recognition ◽  
Standard Deviation ◽  
Clinical Utility ◽  
Clinical Implementation ◽  
Level Difference ◽  
Masking Level Difference ◽  
The Mean ◽  
Abnormal Performance ◽  
Normal Adults

Psychometric functions for the S o N o and Sπ.N o conditions and masking level differences were obtained for a subgroup of 10 words having the largest masking-level differences of 36 CID W-1 spondaic words. The mean masking-level difference obtained from 36 young normal adults was 9.4 dB with a standard deviation of 1.2 dB. The smallest masking-level difference of 7.4 dB was suggested as the low cut-off for normalcy. A shorter version of the masking-level difference procedure was suggested for clinical implementation. The subgroup of 10 words may permit a wider separation between normal and abnormal performance, and thus may enhance the clinical utility of the masking-level difference task for speech recognition. Because the magnitude of the masking-level difference will vary with the materials and procedures used, each clinic must establish its own norms.

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.

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.

Factors Influencing the Masking Level Difference in Cochlear Hearing-Impaired and Normal-Hearing Listeners

1984 ◽  
Vol 27 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Joseph W. Hall ◽  
Richard S. Tyler ◽  
Mariano A. Fernandes
Keyword(s):  
Narrow Band ◽  
Wide Band ◽  
Normal Hearing ◽  
Temporal Coding ◽  
Hearing Impaired ◽  
Frequency Resolution ◽  
Time Discrimination ◽  
Band Noise ◽  
Level Difference ◽  
Masking Level Difference

The masking level difference (MLD) at 500 Hz was examined in wide-band (960 Hz) and narrow-band (50 Hz) noise for normal-hearing subjects and subjects with symmetrical mild-to-moderate cochlear hearing loss. Monaural tasks of intensity discrimination, temporal resolution, and frequency resolution were performed in order to examine relationships between monaural dysfunction and MLD performance. Interaural time discrimination for a 500-Hz pure tone also was examined. The performance of the hearing-impaired subjects was poorer than that of the normal-hearing subjects for MLD, interaural Δt, and most monaural tasks. However, no significant relationships were found between monaural and MLD performance when effects of threshold were taken into account. MLDs were more reduced in wide-band noise than in narrow-band noise for the hearing-impaired subjects (when Contrasted with normal-hearing subjects). MLD performance was correlated with interaural time discrimination, and it is suggested that one reason for poor MLD performance with hearing impairment may be poor temporal coding of stimulus-fine structure.

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