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.

scholarly journals A notched-noise precursor affects both diotic and dichotic notched-noise masking

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 43
Author(s):  
Felix Dymel ◽  
Monika Kordus ◽  
Ifat Yasin ◽  
Jesko L. Verhey
Keyword(s):  
Pure Tone ◽  
Forward Masking ◽  
Noise Masking ◽  
Binaural Cues ◽  
Level Difference ◽  
Masking Level Difference ◽  
Medial Olivocochlear

The present study investigates how diotic and dichotic masked thresholds, in a notched-noise masking paradigm, are affected by activation of the Medial OlivoCochlear (MOC) reflex. Thresholds were obtained for a 500-Hz pure tone diotic or a dichotic signal, S (S0 or Sπ respectively), in the presence of a simultaneous or forward diotic masker (bandpass noise with no notch or a 400-Hz notch). A diotic precursor sound (bandpass noise with a 400- or 800-Hz notch) was presented prior to the signal and masker to activate the MOC reflex. For simultaneous- and forward-masking conditions, the decrease in masked thresholds as a notch was introduced in the masker was larger for the diotic than for the dichotic condition. This resulted in a reduced binaural masking level difference (BMLD) for the masker with a notch. The precursor augmented these two effects. The results indicate that the effect of the precursor, eliciting the MOC reflex, is less pronounced when binaural cues are processed.

Frequency Selectivity and Comodulation Masking Release in Adults and in 6-Year-Old Children

1990 ◽  
Vol 33 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Kathleen Veloso ◽  
Joseph W. Hall ◽  
John H. Grose
Keyword(s):  
Frequency Selectivity ◽  
Center Frequency ◽  
Signal Frequency ◽  
Noise Masking ◽  
Masking Release ◽  
Noise Masker ◽  
Wideband Noise ◽  
Masking Noise ◽  
Comodulation Masking Release ◽  
Narrowband Noise

Frequency selectivity and comodulation masking release (CMR) for a 1000-Hz signal frequency were examined in 6-year-old children and adults. An abbreviated measure of frequency selectivity was also conducted for a 500-Hz signal. Frequency selectivity was measured using a notched-noise masking method, and CMR was measured using narrow bands of noise whose amplitude envelopes were either uncorrelated or correlated. There were 6 listeners in each age group. No differences were observed between the adults and children for either auditory measure. Similarly, no differences were observed in the ability to detect a pure-tone signal in a relatively wideband noise masker. When the masking noise was narrowband, however, the masked thresholds of the children were higher than those of the adults. Two characteristics that distinguish narrowband noise from wideband noise are: (1) narrowband noise has a pitch quality corresponding to its center frequency, whereas wideband noise does not have a definite pitch; (2) the intensity fluctuations are relatively greater in narrowband noise than in wideband noise. This may suggest that 6-year-old children have a reduced ability to detect signals in noise backgrounds where the signal has perceptual qualities similar to the noise, or in noise backgrounds having a high degree of fluctuation.

scholarly journals Speech-evoked Brainstem Auditory Responses and Auditory Processing Skills: A Correlation in Adults with Hearing Loss

2017 ◽  
Vol 22 (01) ◽  
pp. 038-044 ◽  
Author(s):  
Taissane Sanguebuche ◽  
Bruna Peixe ◽  
Rúbia Bruno ◽  
Eliara Biaggio ◽  
Michele Garcia
Keyword(s):  
Hearing Loss ◽  
Auditory Processing ◽  
Auditory Pathway ◽  
Gap Detection ◽  
Behavioral Tests ◽  
Behavioral Skills ◽  
Auditory Responses ◽  
Level Difference ◽  
Masking Level Difference ◽  
Brainstem Response

Introduction The auditory system consists of sensory structures and central connections. The evaluation of the auditory pathway at a central level can be performed through behavioral and electrophysiological tests, because they are complementary to each other and provide important information about comprehension. Objective To correlate the findings of speech brainstem-evoked response audiometry with the behavioral tests Random Gap Detection Test and Masking Level Difference in adults with hearing loss. Methods All patients were submitted to a basic audiological evaluation, to the aforementioned behavioral tests, and to an electrophysiological assessment, by means of click-evoked and speech-evoked brainstem response audiometry. Results There were no statistically significant values among the electrophysiological test and the behavioral tests. However, there was a significant correlation between the V and A waves, as well as the D and F waves, of the speech-evoked brainstem response audiometry peaks. Such correlations are positive, indicating that the increase of a variable implies an increase in another and vice versa. Conclusion It was possible to correlate the findings of the speech-evoked brainstem response audiometry with those of the behavioral tests Random Gap Detection and Masking Level Difference. However, there was no statistically significant correlation between them. This shows that the electrophysiological evaluation does not depend uniquely on the behavioral skills of temporal resolution and selective attention.

scholarly journals Responses of Neurons in the Inferior Colliculus to Binaural Masking Level Difference Stimuli Measured by Rate-Versus-Level Functions

1997 ◽  
Vol 77 (6) ◽  
pp. 3085-3106 ◽  
Author(s):  
Dan Jiang ◽  
David McAlpine ◽  
Alan R. Palmer
Keyword(s):  
Inferior Colliculus ◽  
Discharge Rate ◽  
Detection Threshold ◽  
Low Frequency ◽  
Broadband Noise ◽  
Coincidence Detection ◽  
Level Difference ◽  
Rate Versus ◽  
Versus Level ◽  
Masking Level Difference

Jiang, Dan, David McAlpine, and Alan R. Palmer. Responses of neurons in the inferior colliculus to binaural masking level difference stimuli measured by rate-versus-level functions. J. Neurophysiol. 77: 3085–3106, 1997. The psychophysical detection threshold of a low-frequency tone masked by broadband noise is reduced by ≤15 dB by inversion of the tone in one ear (called the binaural masking level difference: BMLD). The contribution of 120 low-frequency neurons (best frequencies 168–2,090 Hz) in the inferior colliculus (ICC) of the guinea pig to binaural unmasking of 500-Hz tones masked by broadband noise was examined. We measured rate-level functions of the responses to identical signals (So) and noise (No) at the two ears (NoSo) and to identical noise but with the signal inverted at one ear (NoSπ): the noise was 7–15 dB suprathreshold. The masked threshold was estimated by the standard separation, “D”. The neural BMLD was estimated as the difference between the masked thresholds for NoSo and NoSπ. The presence of So and Sπ tones was indicated by discharge rate increases in 55.3% of neurons. In 36.4% of neurons, the presence of So tones was indicated by an increase in discharge rate and Sπ tones by a decrease. In 6.8% of neurons, both So and Sπ tones caused a decrease in discharge rate. In only 1.5% of neurons was So indicated by a decrease and Sπ by an increase in discharge rate. Responses to the binaural configurations were consistent with the neuron's interaural delay sensitivities; 34.4% of neurons showing increases in discharge rate to both So and Sπ tones gave positive BMLDs ≥3 dB (Sπ tones were detected at lower levels than So), whereas 37.3% gave negative BMLDs ≥3 dB. For neurons in which So signals caused an increase in the discharge rate and Sπ a decrease, 72.7% gave positive BMLDs ≥3 dB and only 4.5% gave negative BMLDs ≥3 dB. The results suggest that the responses of single ICC neurons are consistent with the psychophysical BMLDs for NoSo versus NoSπ at 500 Hz, and with current binaural interaction models based on coincidence detection. The neurons likely to contribute to the psychophysical BMLD are those with BFs near 500 Hz, but detection of So and Sπ tones may depend on different populations of neurons.

scholarly journals Treinamento auditivo nas alterações do processamento auditivo: estudo de caso

Revista CEFAC ◽  
2015 ◽  
Vol 17 (2) ◽  
pp. 604-614 ◽  
Author(s):  
Susan Stroiek ◽  
Lenita da Silva Quevedo ◽  
Carla Hernandez Kieling ◽  
Ana Carolina Lago Battezini
Keyword(s):  
Speech Intelligibility ◽  
Gap Detection ◽  
Level Difference ◽  
Pitch Pattern ◽  
Pattern Sequence ◽  
Masking Level Difference

O objetivo deste estudo é verificar a eficácia de um programa de Treinamento Auditivo comparando o desempenho inicial, nos testes de avaliação do processamento auditivo, com o desempenho após o treinamento auditivo. Para este estudo de caso, desenvolvido na clínica de Fonoaudiologia da Universidade de Passo Fundo, foi selecionado um indivíduo que apresentava alterações de linguagem, queixas compatíveis com alterações de processamento auditivo, avaliação audiológica básica normal e avaliação do processamento auditivo alterada. Para isso, foram utilizados os testes Pediatric Speech Intelligibility, Staggered Spondaic Word, Dicótico de Dígitos, Random Gap Detection Test, Masking Level Difference e Pitch Pattern Sequence. Os resultados obtidos na reavaliação com os testes de Processamento Auditivo após oito sessões de treinamento auditivo apontaram melhoras na decodificação e codificação que se encontravam alteradas, persistindo um leve prejuízo na organização. A evolução do indivíduo de grau severo para leve comprova a eficácia do Treinamento Auditivo.

scholarly journals Avaliação do processamento auditivo em operadores de telemarketing

Revista CEFAC ◽  
2006 ◽  
Vol 8 (4) ◽  
pp. 536-542 ◽  
Author(s):  
Maria Cristina Barros da Silva ◽  
Marta Borges Cunha ◽  
Cláudia Célia Lopes Souza ◽  
Edson Ibrahim Mitre
Keyword(s):  
Gap Detection ◽  
Level Difference ◽  
Masking Level Difference ◽  
E 32

OBJETIVO: avaliar o processamento auditivo (PA) dos operadores de telemarketing quanto à decodificação auditiva. Método: foram avaliados 20 sujeitos com idade entre 18 e 35 anos, de ambos os gêneros , com jornada de trabalho de seis horas diárias, e até cinco anos de tempo de serviço na função, usuários de headset monoauricular e sem exposição prévia a ruído ocupacional. O grupo estudado apresenta limiares auditivos dentro dos padrões de normalidade, timpanometria tipo A e reflexos acústicos presentes. Foi aplicado um questionário com objetivo de colher dados quanto às queixas, hábitos e sensações auditivas e foram realizados os testes de processamento de fala filtrada, Random Gap Detection Test (RGDT) e Masking Level Difference (MLD). RESULTADOS: a análise do estudo foi descritiva, por meio de porcentagem onde observou-se que todos os indivíduos (com idade média entre 20 e 32 anos) apresentaram queixas características das desordens do processamento auditivo. Nos testes aplicados foram observadas 45% de alterações no RGDT e 25% no MLD, havendo uma associação entre os testes de MLD alterados e o perfil de atuação no trabalho. CONCLUSÃO: este estudo sugere que o profissional, operador de telemarketing pode apresentar desordens do processamento auditivo, com provável comprometimento da habilidade de interação binaural e resolução temporal as quais mostraram-se alteradas em considerável parte destes indivíduos.

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.

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