Functioning of Olivocochlear Bundle and Speech Perception in Noise

Uppunda, Ajith Kumar; Vanaja, C. S.

doi:10.1097/01.aud.0000120363.56591.e6

Cited by 160 publications

(182 citation statements)

References 18 publications

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“…There are also several other papers that show individual MOCR effects across subjects from which MOCR strength distributions might be calculated (Micheyl et al 1995;Micheyl and Collet 1996;Kumar and Vanaja 2004;Muller et al 2005;Wagner et al 2005Wagner et al , 2007. A major drawback of the De Ceulaer et al distribution is that no information was provided on the amount of measurement error in the data.…”

Section: Comparison With Prior Workmentioning

confidence: 99%

“…For example, the correlation of MOCR strengths from different individuals with results from psychoacoustic tests, such as speech detection in noise, may help to better understand the roles the MOCR plays (Bar-Haim et al 2004;Kumar and Vanaja 2004). Clinically, a reflex strength test may prove useful for screening individuals for susceptibility to acoustic trauma because data from guinea pigs suggest that a stronger reflex affords greater protection (Maison and Liberman 2000).…”

Section: Introductionmentioning

confidence: 99%

“…In other words, when the MOCR_s effect on an SFOAE at a single frequency was normalized by that SFOAE_s amplitude, it would be strongly related to an individual_s MOCR strength throughout the frequency region near the test frequency. We presumed that any randomness in the innervation patterns of individual MOC fibers (Liberman and Brown 1986) would be averaged out because our wideband sound activates many MOC fibers and their effects would be averaged over the relatively wide region of cochlear-amplifier gain that influences an SFOAE. However, to our surprise, we found that such normalized MOCR effects often varied significantly across nearby frequencies within the same individual.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of the Distribution of Medial Olivocochlear Acoustic Reflex Strengths Across Normal-Hearing Individuals via Otoacoustic Emissions

Backus

Guinan

2007

JARO

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A clinical test for the strength of the medial olivocochlear reflex (MOCR) might be valuable as a predictor of individuals at risk for acoustic trauma or for explaining why some people have trouble understanding speech in noise. A first step in developing a clinical test for MOCR strength is to determine the range and variation of MOCR strength in a research setting. A measure of MOCR strength near 1 kHz was made across a normalhearing population (N=25) by monitoring stimulusfrequency otoacoustic emissions (SFOAEs) while activating the MOCR with 60 dB SPL wideband contralateral noise. Statistically significant MOCR effects were measured in all 25 subjects; but not all SFOAE frequencies tested produced significant effects within the time allotted. To get a metric of MOCR strength, MOCR-induced changes in SFOAEs were normalized by the SFOAE amplitude obtained by two-tone suppression. We found this Bnormalized MOCR effect^varied across frequency and time within the same subject, sometimes with significant differences between measurements made as little as 40 Hz apart or as little as a few minutes apart. Averaging several single-frequency measures spanning 200 Hz in each subject reduced the frequency-and time-dependent variations enough to produce correlated measures indicative of the true MOCR strength near 1 kHz for each subject. The distribution of MOCR strengths, in terms of SFOAE suppression near 1 kHz, across our normal-hearing subject pool was reasonably approximated by a normal distribution with mean suppression of approximately 35% and standard deviation of approximately 12%. The range of MOCR strengths spanned a factor of 4, suggesting that whatever function the MOCR plays in hearing (e.g., enhancing signal detection in noise, reducing acoustic trauma), different people will have corresponding differences in their abilities to perform that function.

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Section: Comparison With Prior Workmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of the Distribution of Medial Olivocochlear Acoustic Reflex Strengths Across Normal-Hearing Individuals via Otoacoustic Emissions

Backus

Guinan

2007

JARO

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“…The amplitude of OAE can be reduced by contralateral acoustic stimulation (Warren and Liberman 1989;Collet et al 1990;Ryan et al 1991;Berlin et al 1993b), which is described as OAE suppression effect. This OAE suppression is related to speech understanding in noise (Kumar and Vanaja 2004) and is diminished (or even absent) in patients with speech in noise understanding impairments (Berlin et al 1993a;Starr et al 1996). The frequently observed deterioration of symptoms in APD children in noisy surroundings (ASHA 1996(ASHA , 2005 could point towards a reduced function of the MOCB in this patient group.…”

Section: Discrimination Deficits and Possible Top-down Engagementmentioning

confidence: 99%

Auditory Processing Disorders with and without Central Auditory Discrimination Deficits

Ludwig

Fuchs

Kruse

et al. 2014

JARO

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Auditory processing disorder (APD) is defined as a processing deficit in the auditory modality and spans multiple processes. To date, APD diagnosis is mostly based on the utilization of speech material. Adequate nonspeech tests that allow differentiation between an actual central hearing disorder and related disorders such as specific language impairments are still not adequately available. In the present study, 84 children between 6 and 17 years of age (clinical group), referred to three audiological centers for APD diagnosis, were evaluated with standard audiological tests and additional auditory discrimination tests. Latter tests assessed the processing of basic acoustic features at two different stages of the ascending central auditory system: (1) auditory brainstem processing was evaluated by quantifying interaural frequency, level, and signal duration discrimination (interaural tests). (2) Diencephalic/telencephalic processing was assessed by varying the same acoustic parameters (plus signals with sinusoidal amplitude modulation), but presenting the test signals in conjunction with noise pulses to the contralateral ear (dichotic signal/ noise tests). Data of children in the clinical group were referenced to normative data obtained from more than 300 normally developing healthy school children. The results in the audiological and the discrimination tests diverged widely. Of the 39 children that were diagnosed with APD in the audiological clinic, 30 had deficits in auditory performance. Even more alarming was the fact that of the 45 children with a negative APD diagnosis, 32 showed clear signs of a central hearing deficit. Based on these results, we suggest revising current diagnostic procedure to evaluate APD in order to more clearly differentiate between central auditory processing deficits and higher-order (cognitive and/or language) processing deficits.

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“…The integrity of the MOCS is related to the ability to detect signal in the noise, the thinning of the sequence selectivity, protection against acoustic overstimulation and focusing of attention to an acoustic phenomenon 14 .…”

Section: Introductionmentioning

confidence: 99%

Limiares auditivos tonais, emissões otoacústicas e sistema olivococlear medial de ex-usuários de drogas

2014

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Objetivos analisar se o uso de drogas ilícitas pode interferir nos sistemas auditivos periférico e central. Métodos a amostra foi composta por 17 indivíduos distribuídos conforme o tipo de droga mais consumida: 10 indivíduos no grupo maconha (G1) e sete no grupo crack/cocaína (G2). Os grupos foram subdivididos segundo o tempo de uso de drogas: um a cinco, seis a 10 e mais que 15 anos. Foram avaliados por meio de anamnese, audiometria tonal liminar, imitânciometria, emissões otoacústicas transientes (EOAT) e efeito supressor das EOAT. Resultados comparando os limiares tonais do G1 e G2, observaram-se limiares elevados para o G2, com diferença estatisticamente significante no grupo de um a cinco anos para 250, 500, 6000 e 8000Hz na orelha direita e de seis a 10 anos para 4000 e 8000Hz na orelha esquerda. Para usuários por mais que 15 anos, observou-se limiares superiores a 25dBNA de 3000 a 8000Hz na orelha direita. Nas EOAT e efeito supressor das EOAT não houve diferença estatisticamente significante entre G1 e G2 e entre os tempos de uso das drogas. O G1 apresentou relação sinal/ruído das EOAT superior ao G2. O efeito supressor das EOAT esteve presente em 79% das orelhas avaliadas. Conclusão na amostra estudada, o crack/cocaína apresentou efeito mais deletério sobre o sistema auditivo do que a maconha. O maior tempo de uso de drogas influenciou nos resultados do G1. O uso de drogas ilícitas não provocou alterações no SOCM.

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Functioning of Olivocochlear Bundle and Speech Perception in Noise

Cited by 160 publications

References 18 publications

Measurement of the Distribution of Medial Olivocochlear Acoustic Reflex Strengths Across Normal-Hearing Individuals via Otoacoustic Emissions

Measurement of the Distribution of Medial Olivocochlear Acoustic Reflex Strengths Across Normal-Hearing Individuals via Otoacoustic Emissions

Auditory Processing Disorders with and without Central Auditory Discrimination Deficits

Limiares auditivos tonais, emissões otoacústicas e sistema olivococlear medial de ex-usuários de drogas

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