Contribution of Temporal Fine Structure Cues to Concurrent Vowel Identification and Perception of Zebra Speech.

Introduction The limited access to temporal fine structure (TFS) cues is a reason for reduced speech-in-noise recognition in cochlear implant (CI) users. The CI signal processing schemes like electroacoustic stimulation (EAS) and fine structure processing (FSP) encode TFS in the low frequency whereas theoretical strategies such as frequency amplitude modulation encoder (FAME) encode TFS in all the bands. Objective The present study compared the effect of simulated CI signal processing schemes that either encode no TFS, TFS information in all bands, or TFS only in low-frequency bands on concurrent vowel identification (CVI) and Zebra speech perception (ZSP). Methods Temporal fine structure information was systematically manipulated using a 30-band sine-wave (SV) vocoder. The TFS was either absent (SV) or presented in all the bands as frequency modulations simulating the FAME algorithm or only in bands below 525 Hz to simulate EAS. Concurrent vowel identification and ZSP were measured under each condition in 15 adults with normal hearing. Results The CVI scores did not differ between the 3 schemes (F (2, 28) = 0.62, p = 0.55, η 2 p = 0.04). The effect of encoding TFS was observed for ZSP (F (2, 28) = 5.73, p = 0.008, η 2 p = 0.29). Perception of Zebra speech was significantly better with EAS and FAME than with SV. There was no significant difference in ZSP scores obtained with EAS and FAME ( p = 1.00) Conclusion For ZSP, the TFS cues from FAME and EAS resulted in equivalent improvements in performance compared to the SV scheme. The presence or absence of TFS did not affect the CVI scores.

Effects of Abacus Training on Auditory Spatial Maturation in Children with Normal Hearing

Abstract Introduction The spatial auditory system, though developed at birth, attains functional maturity in the late childhood (12 years). Spatial changes during childhood affect navigation in the environment and source segregation. Accommodation of a new skill through learning, especially during childhood, can expedite this process. Objective To explore the auditory spatial benefits of abacus training on psychoacoustic metrics in children. The study also aimed to identify the most sensitive metric to abacus training related changes in spatial processing, and utilize this metric for a detailed spatial error profiling. Methods A standard group comparison analysis with 90 participants divided into three groups: I: children with abacus training (C-AT); II: children with no training (C-UT); III: adults with no training (A-UT). The groups underwent a series of psychoacoustic tests, such as interaural time difference (ITD), interaural level difference (ILD), and virtual auditory space identification (VASI), as well as perceptual tests such as the Kannada version of the speech, spatial, and quality questionnaire (K-SSQ). Results Significant group differences were observed in the multivariate analysis of variance (MANOVA) and post-hoc tests, with the C-AT group showing significantly lower ILD scores (p = 0.01) and significantly higher VASI scores (p < 0.001) compared to the CUT group, which is indicative of better spatial processing abilities in the former group. The discriminant function (DF) analyses showed that the VASI was the most sensitive metric for training-related changes, based on which elaborate error analyses were performed. Conclusions Despite the physiological limits of the immature neural framework, the performance of the C-AT group was equivalent to that of untrained adults on psychoacoustic tests, which is reflective of the positive role of abacus training in expediting auditory spatial maturation.

Effects of Abacus Training on Auditory Spatial Maturation in Children with Normal Hearing.

Introduction The spatial auditory system, though developed at birth, attains functional maturity in the late childhood (12 years). Spatial changes during childhood affect navigation in the environment and source segregation. Accommodation of a new skill through learning, especially during childhood, can expedite this process. Objective To explore the auditory spatial benefits of abacus training on psychoacoustic metrics in children. The study also aimed to identify the most sensitive metric to abacus training related changes in spatial processing, and utilize this metric for a detailed spatial error profiling. Methods A standard group comparison analysis with 90 participants divided into three groups: I: children with abacus training (C-AT); II: children with no training (C-UT); III: adults with no training (A-UT). The groups underwent a series of psychoacoustic tests, such as interaural time difference (ITD), interaural level difference (ILD), and virtual auditory space identification (VASI), as well as perceptual tests such as the Kannada version of the speech, spatial, and quality questionnaire (K-SSQ). Results Significant group differences were observed in the multivariate analysis of variance (MANOVA) and post-hoc tests, with the C-AT group showing significantly lower ILD scores ( p = 0.01) and significantly higher VASI scores ( p <0.001) compared to the C-UT group, which is indicative of better spatial processing abilities in the former group. The discriminant function (DF) analyses showed that the VASI was the most sensitive metric for training-related changes, based on which elaborate error analyses were performed. Conclusions Despite the physiological limits of the immature neural framework, the performance of the C-AT group was equivalent to that of untrained adults on psychoacoustic tests, which is reflective of the positive role of abacus training in expediting auditory spatial maturation.

Influence of different aspects on psychoacoustic measurements of patients with chronic tinnitus / Influência de diferentes aspectos nas medidas psicoacústicas de pacientes com zumbido crônico

ABSTRACT Purpose: to verify the sex, age, tinnitus location, presence or absence of hearing loss, its degree, and the psychoacoustic measurements (pitch, loudness, minimum masking level [MML], and residual inhibition [RI]) of patients with chronic tinnitus and their relationships. Methods: the study included subjects of both sexes, aged 25 to 85 years, with complaints of chronic tinnitus, followed up at the health service where the research was conducted. They were submitted to medical history survey, basic audiological assessment, and pitch, loudness, RI, and MML research. The following statistical tests were used: chi-square test, Fisher's exact test, Wilcoxon-Mann-Whitney U test, Kruskal-Wallis test, and Spearman's correlation coefficient. The significance level was set at 5% (p≤0.05). Results: the type of tinnitus was associated with the presence or absence of hearing loss (HL), degree of HL, MML, and loudness; age was associated with the presence or absence of HL and its degree. There was a directly weak proportional correlation between loudness and MML, whereas the correlations between pitch and loudness, pitch and MML, and RI and MML were weak and inversely proportional. Conclusion: both the affected subjects and their tinnitus characteristics were heterogeneous. The results indicate that some variables influence one another, which also happens between psychoacoustic measurements.

RESUMO Objetivo: verificar o gênero, a idade, a localização do zumbido, a presença ou ausência de perda auditiva e seu grau, assim como as medidas psicoacústicas (pitch, loudness, nível mínimo de mascaramento e inibição residual) de pacientes com zumbido crônico e as suas relações. Métodos: o estudo incluiu sujeitos de ambos os gêneros, com idades entre 25 e 85 anos, com queixa de zumbido crônico e que realizassem acompanhamento em ambulatório especializado do Hospital de Clínicas de Porto Alegre. Foram submetidos a anamnese, avaliação audiológica básica, pesquisa de pitch, loudness, inibição residual (IR) e nível mínimo de mascaramento (NMM). Foram utilizados os seguintes testes estatísticos: Teste Qui-Quadrado, Teste Exato de Fisher, Teste U de Wilcoxon - Mann-Whitney, Teste Kruskal Wallis e Coeficiente de Correlação de Spearman. O nível de significância utilizado foi de 5% (p≤0,05). Resultados: houve associação entre a variável tipo de zumbido e presença ou ausência de perda auditiva (PA), grau de PA, NMM e loudness, assim como, entre idade e presença ou ausência de PA e seu grau. A loudness e o NMM apresentaram fraca correlação diretamente proporcional, ao passo que as correlações entre pitch e loudness, pitch e NMM e IR versus NMM apresentaram-se fracas e inversamente proporcionais. Conclusão: houve heterogeneidade entre as características do zumbido e dos indivíduos acometidos. Conclui-se, de acordo com os resultados expostos, que existe influência de algumas variáveis entre si, da mesma maneira que ocorre entre as medidas psicoacústicas.

The influence of stimulation levels on auditory thresholds and speech recognition in adult cochlear implant users.

Objective: This study aims to evaluate the influence of minimum and maximum stimulation levels on auditory thresholds and speech recognition abilities in adult cochlear implant users. Method: Fifteen adults implanted with a Cochlear® device with over 12 months listening experience. Participants underwent routine programming for optimization of minimum (T) and maximum comfort (C) stimulation levels, which was saved in Program 1 (MO). Three further maps were constructed artificially adjusting the measured levels: Program 2 - MO with 10 fewer electrical current units at C level (MC-); Program 3 - MO with 10 fewer electric current units at T level (MT-); and Program 4 - MO with 10 more electric current units at T level (MT+). Sound field thresholds, recorded sentence recognition and monosyllable tests were presented in quiet and in noise. Results: There were significantly better thresholds at 1, 3, 4, and 6 kHz frequencies in MT+ and worse in MC-. A statistically significant difference was observed for sentences in quiet and monosyllables in quiet and noise with changing C levels, with worsening of the results for MC- program. Conclusion: The results suggest that T levels above the behavioural threshold provided an improvement in sound field thresholds but did not influence performance on speech recognition tests in quiet and in noise. In contrast, C levels below the behavioural comfort level worsened sound field thresholds and led to poorer performance in tests of sentence recognition in quiet and monosyllable recognition in quiet and in noise.

Recording of tinnitus psychoacoustic measurements: an integrative literature review / Registro de medidas psicoacústicas do zumbido: revisão integrativa

ABSTRACT Purpose: to review both the national and international literature as well as to describe the methods used to collect psychoacoustic measurements in tinnitus patients. Methods: the current integrative review was conducted on articles in specialized national and international journals, in both the Portuguese and English languages, available in the PubMed/Medline, BVS - LILACS and SCIELO databases. The following keywords and descriptors were used: hearing, tinnitus, psychoacoustic measurements, acuphenometry, and assessment, in both the Portuguese and English languages. The retrieved articles were read and selected for the review according to the eligibility criteria, which included the use of psychoacoustic measurements in tinnitus patients and the presence of a detailed methodological description of the protocol employed, in individuals with normal hearing and those with hearing loss. Results: a total of 12 articles, in which psychoacoustic measures were used for the characterization and the measurement of tinnitus in individuals with normal hearing and in those with hearing loss, were reviewed. The main findings were associated with the sample characterization and the way in which the psychoacoustic measures were performed. Conclusion:given the grouping of several protocols for tinnitus evaluation, which were determined following an integrative literature review, a great heterogeneity in the methods used to perform psychoacoustic measurements for tinnitus assessment for both clinical and scientific purposes was noted.

RESUMO Objetivo: revisar a literatura nacional e internacional e descrever os métodos usados para a coleta das medidas psicoacústicas do zumbido. Métodos: essa revisão integrativa foi realizada por meio da busca de artigos em periódicos especializados, nacionais e internacionais, nos idiomas português e inglês, disponíveis nas bases de dados: PubMed/Medline, BVS - LILACS e SCIELO. As palavras-chaves e descritores utilizados foram: audição, zumbido, medidas psicoacústicas, acufenometria e avaliação e, seus correspondentes em inglês. Os artigos levantados foram lidos e selecionados para a revisão seguindo os critérios de elegibilidade: aqueles que empregaram medidas psicoacústicas do zumbido e com descrição metodológica detalhada do protocolo empregado, em indivíduos normo-ouvintes e com perda auditiva. Resultados: foram revisados 12 artigos nos quais as medidas psicoacústicas foram empregadas para a caracterização e mensuração do zumbido, em indivíduos normo-ouvintes e com perda auditiva. Os principais achados referem-se à caracterização da amostra e modo de realização das medidas psicoacústicas. Conclusão: o agrupamento de diversos protocolos para avaliação do zumbido, realizado a partir da revisão integrativa de literatura, evidenciou grande heterogenidade dos métodos de realização das medidas psicoacústicas para a mensuração do zumbido para fins clínicos e científicos.

Psychoacoustics and Neurophysiological Alterations after 30-36 Hours of Sleep Deprivation.

BACKGROUND AND AIM: Sleep deprivation (SD) may result in perceptual and cognitive alterations in healthy subjects. Our objective was to compare whether psychoacoustics and neurophysiological variables in healthy subjects were altered after SD of 30-36 h. METHOD: We examined 22 subjects by means of several psychoacoustics tests, P300 and mismatch negativity (MMN) recordings, and brainstem auditory evoked potentials (BAEP) before and after 30-36 h of SD. RESULTS: In the psychoacoustics tests, we found that after SD, difficulties were experienced by the left ear in the discrimination of words in noise and by the right ear in music discrimination. In the neurophysiological tests, we found delayed latencies of P300 and MMN wave; there was a delay of wave I in both ears, and wave V in the right ear in BAEP. We found significant correlations with positive direction between P300 latency and words in noise and music discrimination in the right ear. CONCLUSIONS: SD results in alterations of central auditory processing perception and delays of brain neurophysiological responses, with some correlations between the psychoacoustics and neurophysiological tests. These alterations may relate to other cognitive alterations that deserve more research in future studies.

Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment.

Previous studies on the effect of spectral content on auditory distance perception (ADP) focused on the physically measurable cues occurring either in the near field (low-pass filtering due to head diffraction) or when the sound travels distances >15 m (high-frequency energy losses due to air absorption). Here, we study how the spectrum of a sound arriving from a source located in a reverberant room at intermediate distances (1-6 m) influences the perception of the distance to the source. First, we conducted an ADP experiment using pure tones (the simplest possible spectrum) of frequencies 0.5, 1, 2, and 4 kHz. Then, we performed a second ADP experiment with stimuli consisting of continuous broadband and bandpass-filtered (with center frequencies of 0.5, 1.5, and 4 kHz and bandwidths of 1/12, 1/3, and 1.5 octave) pink-noise clips. Our results showed an effect of the stimulus frequency on the perceived distance both for pure tones and filtered noise bands: ADP was less accurate for stimuli containing energy only in the low-frequency range. Analysis of the frequency response of the room showed that the low accuracy observed for low-frequency stimuli can be explained by the presence of sparse modal resonances in the low-frequency region of the spectrum, which induced a non-monotonic relationship between binaural intensity and source distance. The results obtained in the second experiment suggest that ADP can also be affected by stimulus bandwidth but in a less straightforward way (i.e., depending on the center frequency, increasing stimulus bandwidth could have different effects). Finally, the analysis of the acoustical cues suggests that listeners judged source distance using mainly changes in the overall intensity of the auditory stimulus with distance rather than the direct-to-reverberant energy ratio, even for low-frequency noise bands (which typically induce high amount of reverberation). The results obtained in this study show that, depending on the spectrum of the auditory stimulus, reverberation can degrade ADP rather than improve it.

Psychoacoustic behavior of human listeners in lateralization judgments of binaural stimuli

Abstract Introduction The present work aims to develop statistical models for the psychoacoustic behavior of human beings in lateralization judgments of binaural acoustic stimuli, as a function of Interaural Time Delay (ITD) and Interaural Amplitude Difference (IAD) for several Sensation Levels (SL). Such models intend to contribute to a deep comprehension of the perception or recognition mechanism which permits listeners to decide whether a source of a sound is located on the right or on the left side of their medial plane. Methods Numerous lateralization judgments are accomplished through a computer controlled experiment set-up in order to investigate the transduction mechanism beneath them. The statistical treatment of the psychoacoustic data obtained has been performed by Two and Three Factors – Probit (Probability Unit) Analysis. Results The Probit Analysis makes it possible to obtain the model coefficients and to fit ‘Probit Planes and Surfaces’ to the experimental data in order to study and predict the simultaneous effects produced by ITD and IAD in the listeners’ psychoacoustic perceptions at several Sensation Levels (SL). Conclusion The approach used here is appropriate for the analysis of this kind of binary response and it also offers a simple way to obtain psychophysical responses that can be related to neurophysiological phenomena. It is argued that this fact may lead to another way to access neural information through psychoacoustic experiments, without needing invasive methods.

A influência das perdas auditivas sensorioneurais na ordenação temporal / The influence of sensoryneural hearing loss on temporal ordering

OBJETIVO: avaliar a ordenação temporal em adultos com perdas auditivas sensorioneurais de graus leve e moderado, por meio do teste Padrão de Duração, a fim de verificar se essas perdas influenciam no desempenho do teste. MÉTODO: foram avaliados 57 pacientes, com idades entre 20 a 59 anos, sendo 30 homens e 27 mulheres. Todos responderam a anamnese, passaram por avaliação otorrinolaringológica, avaliação audiológica básica e triagem do processamento auditivo, com o teste Dicótico de Dígitos. Os participantes foram alocados em 3 grupos: G1 (audição normal para as médias de 0,5/1/2 KHz e de 3/4/6 KHz), G2 (perda auditiva de grau leve em pelo menos uma das médias) e G3 (perda de grau moderado em pelo menos uma das médias). A comparação foi realizada entre a audição normal e a presença da perda auditiva (G2+G3) e entre os três grupos descritos. O índice de normalidade utilizado foi de 70% de acertos. Para a análise estatística foram utilizados os testes não-paramétricos de Mann-Whitney, ANOVA de Kruskal-Wallis, Análise de Variância "one-way", t de Student, Qui-quadrado. O critério de determinação de significância adotado foi o nível de 5%. RESULTADOS: observou-se presença significante de homens no grupo com perda auditiva. A porcentagem de acertos da amostra geral foi de 62,3% e não ocorreu diferença estatisticamente significante entre os grupos. CONCLUSÃO: a habilidade de ordenação temporal avaliada pelo teste Padrão de Duração não sofre influência da perda auditiva sensorioneural de grau leve e moderado.

PURPOSE: to evaluate the temporal ordering ability in adults with mild to moderate sensoryneural hearing loss, through the Duration Pattern Test, in order to determine whether these losses affect the performance of the aforesaid test. METHOD: 57 adults from 20 to 59 years of age were evaluated, being 30 male and 27 female. All of them underwent a screening test consisting of medical history, ENT examination, basic audiological testing and hearing process screening with the Dichotic Digit Test. After this process, the participants were allocated into three groups, namely: G1 (normal hearing for the averages of 0.5 / 1 / 2 and 3/4/6 KHz), G2 (mild hearing loss in at least one of the averages) and G3 (moderate loss in at least one of the averages). The results were analyzed through comparison between normal hearing and the presence of hearing loss (G2 + G3) and among the three groups described. The normality index used was 70% of successes. For statistical analysis, the tests used were Nonparametric Mann-Whitney, Kruskal-Wallis ANOVA, "One-way" Analysis of Variance, student's t and chi-square. The determining criterion of significance adopted was level 5%. RESULTS: there was a significant presence of men with hearing loss in the group. The percentage of correct answers in the overall sample was 62.3%, revealing no statistically significant difference among groups. CONCLUSION: the temporal ordering ability evaluated by the Duration Pattern Test is not influenced by mild to moderate sensoryneural hearing loss.

An experiment set-up for analysis of lateralization judgments of binaural stimuli

INTRODUCTION: The aim of this work is to present a physical implementation of a noninvasive methodology to analyze the directional sensitivity of human auditory system. A computer controlled experiment set-up has been designed and developed to study the behavior of human subjects under the presentation of interaural time delays and interaural amplitude differences for several sensation levels. METHODS: The proposed methodology comprises: the application of trains of low-pass filtered narrow pulses as acoustic binaural stimuli; the automatic, simultaneous and random variation of interaural time delays and interaural amplitude differences; the absence of human interference along the experimental sessions, except for the decision of the listener under test; the minimization of adaptation effects. RESULTS: Numerous lateralization judgments have been accomplished in order to investigate the transduction mechanism which allows deciding which side of subjects medial plane the source of binaural acoustic stimuli is located in. The behavior of decision time with the order of judgment, the sensation levels and the interaural differences in time and amplitudes has been analyzed. CONCLUSION: The noninvasive, reliable and automatic approach here presented allows obtaining psychophysical responses associated to the neuro-physiological phenomena underneath lateralization capability.

Análise da correlação entre limiares auditivos, questionários validados e medidas psicoacústicas em pacientes com zumbido / Correlation analysis of hearing thresholds, validated questionnaires and psychoacoustic measurements in tinnitus patients

Uma das principais dificuldades nos estudos clínicos sobre zumbido reside na falta de consenso sobre os métodos de mensuração. OBJETIVO: Avaliar a correlação entre os limiares audiométricos, pitch matching (PM), minimum masking level (MML), Tinnitus Handicap Inventory (THI) e o Inventário de Depressão de Beck (BDI) em pacientes com zumbido. MODELO DE ESTUDO: Prospectivo, coorte transversal. MATERIAL E MÉTODO: 48 pacientes com zumbido como queixa principal foram submetidos aos testes audiométricos e questionários acima descritos. Os dados foram comparados estatisticamente para as correlações entre os métodos. RESULTADOS: Não houve correlação estatisticamente significativa entre o THI e MML, tanto em pacientes com BDI acima e abaixo de 14 pontos, bem como entre a frequência de pior limiar auditivo e o Pitch matching e entre a frequência de "cut-off" e o PM nos pacientes com curvas descendentes em rampa. CONCLUSÕES: Não existe correlação estatisticamente significativa entre as medidas psicoacústicas do zumbido, os limiares audiométricos e os questionários de avaliação. O zumbido é um sintoma muito complexo e avaliações isoladas pelos métodos acima não são satisfatórias.

One of the most criticized points in tinnitus clinical studies arise from the lack of consensus about measurement methods. AIM: To evaluate the correlation between audiometric thresholds, pitch matching (PM), minimum masking level (MML), Tinnitus Handicap Inventory (THI) and the Beck Depression Inventory (BDI) in tinnitus patients. STUDY DESIGN: Prospective, cross-sectional. MATERIALS AND METHODS: Subjects were submitted to tonal audiometry, PM and MML for tinnitus. They also filled out the THI and BDI. Data was statistically compared for correlation purposes between audiometric thresholds, psycho-acoustic measures and questionnaires. RESULTS: There was no statistically significant correlation between THI and MML, both in patients with BDI scores under and over 14 points. There was no statistically significant correlation between the worst hearing frequency and PM, as well as between the cut-off frequency and the PM in patients with descending hearing curves in their audiograms. CONCLUSIONS: There is no statistically significant correlation between psycho-acoustic measures (PM and MML), audiometric thresholds, THI and BDI. Tinnitus is a very complex symptom and isolated measures by psycho-acoustic methods; tinnitus and depression questionnaires are not satisfactory.

Construção de escalas de diferencial semântico: medida de avaliação de sons no interior de aeronaves / Construction of semantic differential scales: a measure for the evaluation of aircraft interior sound

Este estudo relata a construção de uma medida psicométrica, baseada na técnica do diferencial semântico, para avaliação de propriedades acústicas no interior de aeronaves. Dois estudos compuseram o trabalho: um primeiro estudo da semântica de descritores, e um segundo de construção da medida. Participaram da pesquisa 590 pessoas; o primeiro estudo contou com 298 participantes, sendo 175 do sexo masculino (58,7 por cento). A média de idade foi 23,2 anos (DP = 5,2 anos). No segundo estudo participaram 292 pessoas, 172 do sexo masculino (58,9 por cento); a média de idade foi de 24,2 anos (DP = 6,6 anos). Os resultados do primeiro estudo constituíram uma lista de descritores aptos para caracterização de fenômenos acústicos no interior de aeronaves. O segundo estudo, após análise fatorial, cálculo do coeficiente de confiabilidade alfa de Cronbach e MANOVA, apresentou parâmetros de validade e confiabilidade satisfatórios. A escala final mensurou quatro fatores: Avaliação, Adequação, Estabilidade e Intensidade.(AU)

This study reports the construction of a psychometrical measure, based on the semantic differential technique, for acoustic properties' evaluation in aircraft interiors. Two studies composed the research: a first study of semantic descriptors, and a second one for measure construction. Five hundred and ninety people took part on the research. The first study had 298 participants, 175 were male (58,7 percent). The mean age was 23,2 years old (SD = 5,2 years). On the second study 292 people participated, 172 of whom were male (58,9 percent), and the mean age was 24,2 years old (SD = 6,6 years). The results of the first study provided a list of descriptors able to describe acoustic phenomena in aircraft interiors. The second study, after factor analysis and determination of Cronbach's alpha reliability index and MANOVA, presented satisfactory validity and reliability parameters. The final scale measured four factors: Appreciation, Adequacy, Stability and Intensity.(AU)

Processamento auditivo, resolução temporal e teste de detecção de gap: revisão da literatura: [revisão] / Auditory processing, temporal resolution and gap detection test: literature review: [review]

TEMA: processamento auditivo temporal e resolução temporal. OBJETIVO: realizar revisão teórica sobre processamento auditivo e resolução temporal, bem como sobre os diferentes parâmetros de marcadores utilizados em testes de detecção de gap e como eles podem interferir na determinação dos limiares. CONCLUSÃO: o processamento auditivo e a resolução temporal são fundamentais para o desenvolvimento da linguagem. Em virtude dos diferentes parâmetros que podem ser utilizados no teste em questão, os limiares de detecção de gap podem variar consideravelmente.

BACKGROUND: temporal auditory processing and temporal resolution. PURPOSE: promote a theoretical approach on auditory processing, temporal resolution, and different parameters of markers used at various gap detection tests and how they can interfere in threshold determination. CONCLUSION: auditory processing and temporal resolution are key-factors for language development. The diverse parameters that can be used in the study of gap detection thresholds can result in quite discrepant thresholds.