O trabalho teve como objetivo geral discutir a construção de listas de palavras para uso na medida do teste de Limiar de Reconhecimento da Fala (LRF) em crianças com idade entre 5 e 7 anos. O grupo de sujeitos foi constituído por alunos de pré-escola e da 1ª série do ensino fundamental de escolas da rede pública da cidade de Itatiba, São Paulo, otologicamente normais. O trabalho foi estruturado em 3 etapas. A primeira etapa relacionou-se com a construção das listas de palavras experimentais trissilábicas paroxítonas denominadas de LE1 e 2, constituídas a partir de um levantamento feito com programas e filmes infantis de maior audiência pelos grupos etários estudados. Das 672 palavras obtidas, 35 trissílabas paroxítonas foram selecionadas, formando duas listas em ordem aleatória. As listas LRS 1 e 2 foram utilizadas para comparação e retiradas de Russo e Santos (1993), seguindo os mesmos critérios de elaboração. Na segunda etapa, as listas de palavras foram gravadas em estúdio profissional, por um locutor do sexo feminino nativo do português brasileiro. Na terceira etapa o material desenvolvido foi aplicado em um grupo de 94 crianças de 5 a 7 anos de ambos os sexos. Os resultados, na análise quantitativa, não mostraram diferenças estatisticamente significantes entre as variáveis listas, orelhas, faixa etária, ordem de apresentação e sexo. Os resultados do LRF (em deciBel Nível de Sensação) obtidos com as listas LE e LRS situaram-se entre -10 e +15dBNS com média de 4,3dBNS para orelha direita e 4,4dBNS para orelha esquerda. Os dados indicaram que as listas desenvolvidas para a obtenção do LRF, em crianças na faixa etária do estudo, são válidas para este fim. A análise qualitativa indicou algumas das estratégias utilizadas pelos sujeitos no reconhecimento auditivo das palavras da lista E1. / This study provides a discussion about a word list construction to use in the speech recognition threshold. The chosen subjects are pre and first year school children from the Basic Education at public schools in Itatiba, São Paulo – Brazil, otologically normal. The study comprises three stages. The first one was the construction of paroxytone trisyllabic word lists called LE1 e 2, consisted of a survey done with juvenile programs and films of bigger audience by the aged studied groups. From the 672 words, 35 paroxytone trisyllables were selected, forming two lists in a random order. The LRS 1 and 2 were used for comparison and they were got from Russo e Santos (1993), following the same criteria. In the second stage, the word lists were recorded in a professional studio by a native speaker. In the third stage, the developed material was applied in a group with 94 children. The results didn’t show differences statistically significant among the varied list, the ear, the aged group, the presentation order and the sex. The SRT (dBNS) results obtained with the LE and the LRS lists were placed among -10 and +15 dBNS. The data indicated that the developed lists to obtain the SRT in these children are valid.

Human auditory perception is suited to receiving and interpreting information from the environment but this knowledge has not been used extensively in designing computer-based information exploration tools. It is not known which aspects of sound are useful for accurately conveying information in an auditory display. An auditory display was created using PD, a graphical programming language used primarily to manipulate digital sound. The interface for the auditory display was a blank window. When the cursor is moved around in this window, the sound generated would changed based on the underlying data value at any given point. An experiment was conducted to determine which attribute of sound most accurately represents data values in an auditory display. The four attributes of sound tested were frequency-sine waveform, frequency-sawtooth waveform, loudness and tempo. 24 subjects were given the task of finding the highest data point using sound alone using each of the four sound treatments. Three dependent variables were measured: distance accuracy, numeric accuracy, and time on task. Repeated measures ANOVA procedures conducted on these variables did not rise to the level of statistical significance (α=.05). None of the sound treatments was more accurate than the other as representing the underlying data values. 52% of the trials were accurate within 50 pixels of the highest data point (target). An interesting finding was the tendency for the frequency-sin waveform to be used in the least accurate trial attempts (38%). Loudness, on the other hand, accounted for very few (12.5%) of the least accurate trial attempts. In completing the experimental task, four different search techniques were employed by the subjects: perimeter, parallel sweep, sector, and quadrant. The perimeter technique was the most commonly used.

Les études de bioacoustique animale, qui reposent traditionnellement sur des modèles primates non humains et oiseaux chanteurs, convergent vers l'idée que la vie sociale serait la principale force motrice de l'évolution de la complexité de la communication. La comparaison avec les cétacés est également particulièrement intéressante d'un point de vue évolutif. Ce sont des mammifères qui forment des liens sociaux complexes, ont des capacités de plasticité acoustique, mais qui ont dû s'adapter à la vie marine, faisant de l'habitat une autre force de sélection déterminante. Leur habitat naturel impose des contraintes sur la production sonore, l'utilisation et la perception des signaux acoustiques, mais, de la même manière, limite les observations éthologiques. Etudier les cétacés captifs devient alors une source importante de connaissances sur ces animaux. Au-delà de l'analyse des structures acoustiques, l'étude des contextes sociaux dans lesquels les différentes vocalisations sont utilisées est essentielle à la compréhension de la communication vocale. Par rapport aux primates et aux oiseaux, la fonction sociale des signaux acoustiques des dauphins reste largement méconnue. En outre, les adaptations morpho-anatomiques de l’appareil vocal et auditif des cétacés à une vie sous-marine sont uniques dans le règne animal. Leur capacité à percevoir les sons produits dans l'air reste controversée en raison du manque de démonstrations expérimentales. Les objectifs de cette thèse étaient, d'une part, d'explorer l'utilisation contextuelle spontanée des signaux acoustiques dans un groupe captif de dauphins et, d'autre part, de tester expérimentalement les capacités à percevoir les sons sous l’eau comme dans l’air. Notre première étude observationnelle décrit la vie quotidienne de dauphins en captivité et montre que les signaux vocaux reflètent, à grande échelle, la répartition temporelle des activités sociales et non sociales dans un établissement sous contrôle humain. Notre deuxième étude met l'accent sur le contexte d’émission des trois principales catégories acoustiques précédemment identifiées dans le répertoire vocal des dauphins, à savoir les sifflements, les sons pulsés et les séries de clics. Nous avons trouvé des associations préférentielles entre chaque catégorie vocale et certains types d'interactions sociales ainsi que des combinaisons sonores non aléatoires et également dépendantes du contexte. Notre troisième étude a testé expérimentalement, dans des conditions standardisées, la réponse des dauphins à des « labels » acoustiques individuels donnés par l’homme et diffusés dans l’eau et dans l’air. Nous avons constaté que les dauphins peuvent reconnaître et réagir uniquement à leur propre « label » sonore, même lorsqu'il est diffusé dans l’air. En plus de confirmer l'audition aérienne, ces résultats soutiennent l’idée que les dauphins possèdent une notion d'identité. Dans l'ensemble, les résultats obtenus au cours de cette thèse suggèrent que certains signaux sociaux dans le répertoire des dauphins peuvent être utilisés pour communiquer des informations spécifiques sur les contextes comportementaux des individus impliqués et que les individus sont capables de généraliser leur concept d'identité à des signaux générés par l'homme. / Studies on animal bioacoustics, traditionally relying on non-human primate and songbird models, converge towards the idea that social life appears as the main driving force behind the evolution of complex communication. Comparisons with cetaceans is also particularly interesting from an evolutionary point of view. They are indeed mammals forming complex social bonds, with abilities in acoustic plasticity, but that had to adapt to marine life, making habitat another determining selection force. Their natural habitat constrains sound production, usage and perception but, in the same way, constrains ethological observations making studies of captive cetaceans an important source of knowledge on these animals. Beyond the analysis of acoustic structures, the study of the social contexts in which the different vocalizations are used is essential to the understanding of vocal communication. Compared to primates and birds, the social function of dolphins’ acoustic signals remains largely misunderstood. Moreover, the way cetaceans’ vocal apparatus and auditory system adapted morphoanatomically to an underwater life is unique in the animal kingdom. But their ability to perceive sounds produced in the air remains controversial due to the lack of experimental demonstrations. The objectives of this thesis were, on the one hand, to explore the spontaneous contextual usage of acoustic signals in a captive group of bottlenose dolphins and, on the other hand, to test experimentally underwater and aerial abilities in auditory perception. Our first observational study describes the daily life of our dolphins in captivity, and shows that vocal signalling reflects, at a large scale, the temporal distribution of social and non-social activities in a facility under human control. Our second observational study focuses on the immediate context of emission of the three main acoustic categories previously identified in the dolphins’ vocal repertoire, i.e. whistles, burst-pulses and click trains. We found preferential associations between each vocal category and specific types of social interactions and identified context-dependent patterns of sound combinations. Our third study experimentally tested, under standardized conditions, the response of dolphins to human-made individual sound labels broadcast under and above water. We found that dolphins were able to recognize and to react only to their own label, even when broadcast in the air. Apart from confirming aerial hearing, these findings go in line with studies supporting that dolphins possess a concept of identity. Overall, the results obtained during this thesis suggest that some social signals in the dolphin repertoire can be used to communicate specific information about the behavioural contexts of the individuals involved and that individuals are able to generalize their concept of identity for human-generated signals.

The purpose of this study was to investigate the effects of three different levels of skill training in musical timbre discrimination on alphabet sound discrimination in pre-kindergarten and kindergarten children. The findings of prior investigations indicated similarities between aural music and language perception. Psychoacoustic and neurological findings have reported the discrimination of alphabet quality and musical timbre to be similar perceptual functions and have provided, through imaging technology, physical evidence of music learning simultaneously stimulating non-musical areas of the brain. This investigator hypothesized that timbre discrimination, the process of differentiating the characteristic quality of one complex sound from another of identical pitch and loudness, may have been a common factor between music and alphabet sound discrimination. Existing studies had not explored this relationship or the effects of directly teaching for transfer on learning generalization between skills used for the discrimination of musical timbre and alphabet sounds. Variables identified as similar from the literature were the discrimination of same- different musical and alphabet sounds, visual recognition of musical and alphabet pictures as sound sources, and association of alphabet and musical sounds with matching symbols. A randomized pre-post test design with intermittent measures was used to implement the study. There were 5 instructional groups. Groups 1, 2,and 3 received one, two and three levels of skill instruction respectively. Groups 4 received three levels of skill training with instruction for transfer; Group 5 traditional timbre instruction. Students were measured at the 5th (Level 1), 10th (Level 2), 14th (Level 3), and 18th (delayed re-test), weeks of instruction. Results revealed timbre discrimination instruction had a significant impact on alphabet sound-symbol discrimination achievement in pre-kindergarten and kindergarten children. Different levels of timbre instruction had different degrees of effectiveness on alphabet sound discrimination. Students who received three levels of timbre discrimination instruction and were taught to transfer skill similarities from music timbre discrimination to alphabet sound discrimination, were significantly more proficient in alphabet sound symbol discrimination than those who had not received instruction Posttest comparisons indicated skill relationships were strengthened by instruction for transfer. Transfer strategies had a significant impact on the retention of newly learned skills over time.

his study compared auditory behavioral and physiological measures among three subject groups: 1) Normal control subjects, 2) subjects who were on a prescribed SSRI for depression, and 3) subjects who were prescribed an SSRI for depression, but were not medicated at the time of testing. Test measures included: Standard audiological tests (audiometry and tympanometry), electrophysiological procedures for analysis of auditory- evoked brainstem and late responses, and standardized behavioral speech tests (SCAN-A, SSI, and the low predictability sentence list of the R-SPIN). Analysis of results indicated a statistically significant increase of group mean amplitude of the ABR peak V, from 15dBnSL to 55dBnSL, in the non-medicated group compared to controls. Also, the non-medicated group scored significantly less favorably than controls on the most challenging listening condition (-20 MCR) of the SSI, in the left ear. Although other test measures indicated consistent differences between these two groups, they were not, however, significant.

The purpose of this study was to investigate the relationship between selective serotonin reuptake inhibitor (SSRI) medication on auditory skills in clinically depressed subjects. Experimental subjects prescribed an SSRI were tested in a medicated and an unmedicated condition, and the test results were compared. Furthermore, the experimental group was compared with a control group consisting of normal subjects. Test measures included pure tone audiometry, tympanometry, acoustic reflex thresholds, and auditory electrophysiologic measures such as auditory brainstem and auditory late responses. An assessment scale for depression (Beck Depression Inventory-II) was also used. Results indicated statistically significant differences for the BDI-II between the control and experimental groups for both conditions. Electrophysiologic measures indicated a significantly shorter latency for auditory late potential P1 at 55 dBnSL, and a significantly larger amplitude at 45 dBnSL for the N1/P2 component for the unmedicated group. Although the other measures showed trends, they did not reach significance.

Speech perception typically takes place within the auditory cortex as evidenced by data collected using quantitative electroencephalography (qEEG). The purpose of this study was to determine if motor responses influence speech perception. We examined P300 event-related potentials during oddball stimulus recognition tasks that either required or did not require a motor response. Based on a review of the literature, it was hypothesized that similar areas of the brain would be activated in both the motor response task and the same task without a motor response immediately following the button-push condition. Two syllables, /ba/ and /ga/, were presented to 20 native English speakers (10 females and 10 males) between the ages of 19 and 30 years. An oddball paradigm consisting of standard and deviant stimuli was presented in three trials: passive listening, mental counting, and button-push. Participants were randomly assigned an order to the trials for passive listening and mental count; however, the button-push response was completed second each time. Data from event-related potentials were recorded for each participant using qEEG and combined across participants to create grand averaged waveforms. Cortical regions of activation were identified and compared across conditions. Results showed that different cortical areas were activated when the mental counting and passive listening conditions were done before and after the motor response condition. Requiring a more complicated response than is typically used to discriminate phonemes, such as with the button push response, may alter speech perception based on the cortical regions activated as measured through source localization. Further research on latencies and amplitudes of the even-related potential (ERP) waveforms is needed to determine how speech perception changes.

The new compact disc from the Department of Veterans Affairs, Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 2.0 (1998), contains two lists of randomly interleaved 1-, 2-, and 3-pair dichotic digits. Two experiments are reported, in which the effects of low-pass filtering and inter-digit interval on dichotic digit recognition were investigated in adult listeners with normal hearing and with mild-to-moderate cochlear hearing loss. Results demonstrated that in the filtered condition, as the low-pass cutoff was increased, there was an increase in recognition performance for 1-, 2-, and 3-pair dichotic digits. When compared to normative data for the materials, findings indicate that the interleaved 1-, 2-, and 3-pair dichotic digit materials were essentially resistant to the effects of hearing loss. There was no significant change in recognition performance as a function of inter-digit interval. The studied 625-ms range of inter-digit intervals studied produced consistent recognition performance with both groups of listeners.

Dichotic listening was evaluated in free-recall and directed-recall (pre-cued, post-cued) response conditions using interleaved one-, two-, and three-pair dichotic digit materials. In the free-recall condition, the subjects recalled in any order the digits presented. In the directed-recall condition, a response task was examined where subjects recalled all digits presented to the cued ear (pre- or post-cued) followed by the digits presented to the opposite (non-cued) ear. Thirty 20- to 29-year-old adults with normal hearing and 30 60- to 79-year-old adults with mild-to-moderate sensorineural hearing loss were evaluated. In all conditions, performance by the younger listeners was better than performance by the elderly listeners. As the difficulty of the dichotic digit task increased, recognition performance decreased. The recognition performance of elderly listeners was more affected by increases in the difficulty of the stimulus materials as compared to the younger listeners. In the free-recall condition, there was a right-ear advantage for both age groups. When instructional bias was imposed, the results favored the ear of instructed bias. The differences in recognition performance between young and elderly listeners likely reflect differences in the difficulty of the dichotic digit test conditions and variations in the demand on auditory memory.

Objective: To examine the effectiveness of the Listening and Communication Enhancement (LACE) program as a supplement to standard-of-care hearing aid intervention in a Veteran population. Design: A multisite randomized controlled trial was conducted to compare outcomes following standard-of-care hearing aid intervention supplemented with (1) LACE training using the 10-session DVD format, (2) LACE training using the 20-session computer-based format, (3) placebo auditory training (AT) consisting of actively listening to 10 hr of digitized books on a computer, and (4) educational counseling - the control group. The study involved 3 VA sites and enrolled 279 veterans. Both new and experienced hearing aid users participated to determine if outcomes differed as a function of hearing aid user status. Data for five behavioral and two self-report measures were collected during three research visits: baseline, immediately following the intervention period, and at 6 months postintervention. The five behavioral measures were selected to determine whether the perceptual and cognitive skills targeted in LACE training generalized to untrained tasks that required similar underlying skills. The two self-report measures were completed to determine whether the training resulted in a lessening of activity limitations and participation restrictions. Outcomes were obtained from 263 participants immediately following the intervention period and from 243 participants 6 months postintervention. Analyses of covariance comparing performance on each outcome measure separately were conducted using intervention and hearing aid user status as between-subject factors, visit as a within-subject factor, and baseline performance as a covariate. Results: No statistically significant main effects or interactions were found for the use of LACE on any outcome measure. Conclusions: Findings from this randomized controlled trial show that LACE training does not result in improved outcomes over standard-of-care hearing aid intervention alone. Potential benefits of AT may be different than those assessed by the performance and self-report measures utilized here. Individual differences not assessed in this study should be examined to evaluate whether AT with LACE has any benefits for particular individuals. Clinically, these findings suggest that audiologists may want to temper the expectations of their patients who embark on LACE training.