A theory of the segmental component of speech motor control is presented, followed by supporting data. According to the theory, speech movements are programmed to achieve auditory/acoustic goals. The goals are determined partly by "saturation effects", which are basic characteristics of speakers' production systems that make it possible to produce a sound output that has some relatively stable acoustic properties despite a somewhat variable motor input. The programming of articulatory movements to achieve auditory goals utilizes an internal model (or "mapping") of relations between articulatory configurations and their acoustic consequences. The internal model is acquired and maintained with the use of auditory feedback. The supporting data for this theory come from experiments on speakers with normal hearing, cochlear implant users and a patient with neurofibromatosis-2.

A theory of speech motor control and supporting data from speakers with normal hearing and with profound hearing loss

Currently, there are two major hypotheses concerning the nature of developmental APD. One is conventional, that APD results from impaired ‘bottom-up’ processing of sounds. However, while a conventional view suggests the problem with APD lies in the central auditory nervous system (CANS), we propose that the problem may lie more peripherally, possibly in the ear. Alternatively, processing problems expressed in the ear, hindbrain or auditory cortex could reflect the second hypothesis, ‘top-down’ influences from cortical cognitive processing centers that may exert their influence on the auditory cortex, and be conveyed to lower targets via CANS efferent pathways. A variant of this hypothesis is that the problem may be entirely cognitive, primarily affecting language processing, attention or memory and exerting a non-specific (e.g. supramodal) effect on perception. Whichever of these hypotheses turns out to be correct, we propose that the very high co-occurrence of APD with a wide variety of other aud...

Auditory processing disorder (APD) in children: A marker of neurodevelopmental syndrome

Energy efficiency versus indoor environmental quality in different Romanian countryside schools

Objectives Permanent threshold elevation after noise exposure, ototoxic drugs, or aging is caused by loss of sensory cells; however, animal studies show that hair cell loss is often preceded by degeneration of synapses between sensory cells and auditory nerve fibers. The silencing of these neurons, especially those with high thresholds and low spontaneous rates, degrades auditory processing and may contribute to difficulties in understanding speech in noise. Although cochlear synaptopathy can be diagnosed in animals by measuring suprathreshold auditory brainstem responses, its diagnosis in humans remains a challenge. In mice, cochlear synaptopathy is also correlated with measures of middle ear muscle (MEM) reflex strength, possibly because the missing high-threshold neurons are important drivers of this reflex. The authors hypothesized that measures of the MEM reflex might be better than other assays of peripheral function in predicting difficulties hearing in difficult listening environments in human subjects. Design The authors recruited 165 normal-hearing healthy subjects, between 18 and 63 years of age, with no history of ear or hearing problems, no history of neurologic disorders, and unremarkable otoscopic examinations. Word recognition in quiet and in difficult listening situations was measured in four ways: using isolated words from the Northwestern University auditory test number six corpus with either (a) 0 dB signal to noise, (b) 45% time compression with reverberation, or (c) 65% time compression with reverberation, and (d) with a modified version of the QuickSIN. Audiometric thresholds were assessed at standard and extended high frequencies. Outer hair cell function was assessed by distortion product otoacoustic emissions (DPOAEs). Middle ear function and reflexes were assessed using three methods: the acoustic reflex threshold as measured clinically, wideband tympanometry as measured clinically, and a custom wideband method that uses a pair of click probes flanking an ipsilateral noise elicitor. Other aspects of peripheral auditory function were assessed by measuring click-evoked gross potentials, that is, summating potential (SP) and action potential (AP) from ear canal electrodes. Results After adjusting for age and sex, word recognition scores were uncorrelated with audiometric or DPOAE thresholds, at either standard or extended high frequencies. MEM reflex thresholds were significantly correlated with scores on isolated word recognition, but not with the modified version of the QuickSIN. The highest pairwise correlations were seen using the custom assay. AP measures were correlated with some of the word scores, but not as highly as seen for the MEM custom assay, and only if amplitude was measured from SP peak to AP peak, rather than baseline to AP peak. The highest pairwise correlations with word scores, on all four tests, were seen with the SP/AP ratio, followed closely by SP itself. When all predictor variables were combined in a stepwise multivariate regression, SP/AP dominated models for all four word score outcomes. MEM measures only enhanced the adjusted r values for the 45% time compression test. The only other predictors that enhanced model performance (and only for two outcome measures) were measures of interaural threshold asymmetry. Conclusions Results suggest that, among normal-hearing subjects, there is a significant peripheral contribution to diminished hearing performance in difficult listening environments that is not captured by either threshold audiometry or DPOAEs. The significant univariate correlations between word scores and either SP/AP, SP, MEM reflex thresholds, or AP amplitudes (in that order) are consistent with a type of primary neural degeneration. However, interpretation is clouded by uncertainty as to the mix of pre- and postsynaptic contributions to the click-evoked SP. None of the assays presented here has the sensitivity to diagnose neural degeneration on a case-by-case basis; however, these tests may be useful in longitudinal studies to track accumulation of neural degeneration in individual subjects.

Middle Ear Muscle Reflex and Word Recognition in "Normal-Hearing" Adults: Evidence for Cochlear Synaptopathy?

OBJETIVO: Identificar se existe correlacao entre ruido ambiental no interior da sala de aula, intensidade da voz e presenca de alteracao vocal em professores. METODOS: Foi realizada medicao do ruido ambiental em dez salas de escolas municipais de ensino fundamental. A intensidade das vozes das professoras foi medida durante atividade de ensino. Amostras de vogal prolongada [e] e contagem de 1 a 20 emitidas pelas professoras foram analisadas utilizando escala GRBASI. Os resultados obtidos foram correlacionados. RESULTADOS: A media de ruido ambiental sem a presenca das criancas em sala de aula variou de 40 a 51 dB(A) e com a presenca das criancas de 45 a 65 dB(A). Entre as professoras, houve 70% de ocorrencia de vozes alteradas no grau geral (G) e 90% com tensao na voz (S), variando entre graus discreto e moderado. Constatou-se variacao entre 52 dB(A) e 68 dB(A) na intensidade da voz das professoras, atingindo 7,48 dB(A) acima do nivel do ruido ambiental. Houve correlacao entre a intensidade vocal das professoras e ruido ambiental na presenca das criancas durante a aula. CONCLUSAO: Os niveis de ruido ambiental em sala de aula sao altos e se correlacionam com o aumento da intensidade das vozes das professoras. Embora com alta ocorrencia de vozes alteradas, nao e possivel correlaciona-las com o nivel de ruido ambiental.

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Correlações entre ruído ambiental em sala de aula e voz do professor

TEMA: a influencia do ambiente acustico na aprendizagem. OBJETIVO: analisar alteracoes que podem ocorrer aos estudantes de uma escola que se encontre sob impacto de ruidos internos ou externos as suas instalacoes.Para isso, foi realizada uma revisao da literatura sobre temas: processamento auditivo, percepcao de fala, acustica em sala de aula, nocoes basicas de ruido. CONCLUSAO: a escola se encontra sob forte impacto de ruidos diversos, que se tornam opositores invisiveis a aprendizagem, em um local onde a situacao de escuta deveria ser muito privilegiada, e que os Fonoaudiologos podem auxiliar uma equipe multidisciplinar no monitoramento destas areas e na implantacao de programas de conservacao auditiva.

/pdf/noise-and-its-interference-over-students-in-a-classroom-1fpdjdpo7y.pdf

[Noise and its interference over students in a classroom environment: literature review].

PURPOSE: To compare the performances of young and elderly women on the Random Gap Detection Test (RGDT). METHODS: Seventy two women were evaluated, distributed in two groups: Control Group (CG), composed by 48 young women (mean age = 23.8 years) with normal peripheral hearing, and Experimental Group (EG), composed by 24 elderly women (mean age = 66.8 years) with normal peripheral hearing or mild sensorineural hearing loss. Both groups were submitted to the RGDT for pure-tones, in the frequencies of 500, 1000, 2000 and 4000 Hz. RESULTS: All subjects from CG identified gaps up to 40 ms in all tested frequencies, with average gap of 12.2 ms among them. In the EG, it was observed that 20 out of the 24 subjects did not identify intervals up to 40 ms in one or more frequencies. Data analysis showed statistically significant differences between the performances of the groups (p<0001). CONCLUSIONS: Age increase was shown as an aggravating factor for performance on the RGDT. This test proved to be a valuable tool for the evaluation of aging effects on auditory temporal resolution ability.

https://www.scielo.br/pdf/rsbf/v14n4/a13v14n4.pdf

Desempenho no Teste de Detecção de Intervalo Aleatório - Random Gap Detection Test (RGDT): estudo comparativo entre mulheres jovens e idosas

Introduction For infants under 6 months, the literature recommends 1,000-Hz tympanometry, which has a greater sensitivity for the correct identification of middle ear disorders in this population. Objective To systematically analyze national and international publications found in electronic databases that used tympanometry with 226-Hz and 1,000-Hz probe tones. Data Synthesis Initially, we identified 36 articles in the SciELO database, 11 in the Latin American and Caribbean Literature on the Health Sciences (LILACS) database, 199 in MEDLINE, 0 in the Cochrane database, 16 in ISI Web of Knowledge, and 185 in the Scopus database. We excluded 433 articles because they did not fit the selection criteria, leaving 14 publications that were analyzed in their entirety. Conclusions The 1,000-Hz tone test has greater sensitivity and specificity for the correct identification of tympanometric curve changes. However, it is necessary to clarify the doubts that still exist regarding the use of this test frequency. Improved methods for rating curves, standardization of normality criteria, and the types of curves found in infants should be addressed.

/pdf/tympanometry-in-infants-a-study-of-the-sensitivity-and-2p7qyx1eju.pdf

Tympanometry in Infants: A Study of the Sensitivity and Specificity of 226-Hz and 1,000-Hz Probe Tones

A interferência do ruído na aprendizagem

OBJETIVO: Descrever os achados da avaliacao de habilidades auditivas - tracos de frequencia, intensidade e duracao - em um grupo de professores disfonicos (GD), comparando-os aos encontrados em professores nao-disfonicos (GND). METODOS: Foram avaliados 44 sujeitos do genero feminino, na faixa etaria de 18 a 40 anos, sendo 23 disfonicos (GD) e 21 nao-disfonico (GND). Para definir esses grupos, as professoras foram submetidas a avaliacao laringologica e perceptivo-auditiva da voz, bem como, a avaliacao audiologica completa, a fim de que fossem excluidas aquelas que apresentassem perda auditiva. Apos a selecao, procedeu-se a investigacao do Limiar Diferencial de Intensidade e da aplicacao dos Testes de Deteccao de Padrao de Frequencia e Duracao. RESULTADOS: O GND apresentou melhor desempenho que o GD na avaliacao do parâmetro de frequencia. CONCLUSAO: A analise relacionada a percepcao auditiva mostra diferenca apenas para o parâmetro da frequencia entre professores disfonicos e nao disfonicos. Estudos com maior numero de sujeitos e com outros testes que avaliem o limiar diferencial de intensidade podem esclarecer melhor a relacao entre problemas de voz e dificuldades na percepcao de pequenas diferencas de intensidade.

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Teresa Maria Momensohn-Santos

Papers

[Noise and its interference over students in a classroom environment: literature review].

Desempenho no Teste de Detecção de Intervalo Aleatório - Random Gap Detection Test (RGDT): estudo comparativo entre mulheres jovens e idosas

Tympanometry in Infants: A Study of the Sensitivity and Specificity of 226-Hz and 1,000-Hz Probe Tones

A interferência do ruído na aprendizagem

Percepção auditiva de professores disfônicos