Four studies were undertaken to investigate the advance planning and perception of simple rhythmic patterns. Subjects listened to patterns of identical, computer-generated tones and then reproduced them as accurately as possible by tapping on a single response key. Section One focussed on the advance planning of isochronous rhythmic patterns in which subjects performed the additional task of initiating pattern reproduction as quickly as possible. In Experiment 1, subjects listened to patterns of one to six tones with interstimulus intervals (ISIs) of 300 ms. The reproduction phase involved no stimulus uncertainty. Reaction time (RT) was found to increase linearly with number of response events. Advance planning thus occurs for patterns reproduced as slow as 300 ms per response event. Stimulus uncertainty is not a necessary condition for RT to increase with response complexity. In Experiment 2, subjects reproduced patterns of one to eight tones with ISIs of 200, 400, 600, and 800 ms. A linear RT trend was found only at the 200-ms rate. Patterns slower than this rate did not display "response coherence". Patterns at the 200-ms and 400-ms rates showed evidence of grouping through the accenting of first and last intervals. These patterns' displayed "perceptual coherence". Section Two focussed on the perceptual organization of patterns in which pattern structures could suggest the grouping of events as two equal-duration intervals. In Experiment 3, subjects reproduced two series of patterns, one series in which the suggested grouping-intervals were initiated by external-world events, and one in which they were not. Pattern structures in the latter series were not suggestive enough to induce grouping of events as two equal-duration intervals. Patterns were instead grouped as two intervals of unequal duration showing that the relative temporal positions of external-world events dominates in simple perceptual grouping. Experiment 4 investigated the upper temporal limit of perceptual grouping intervals and the influence of number of group constituents. Results showed that perceptual grouping of events that span more than 1800 ms is seldom accomplished and that grouping occurs when intervals contain up to seven constituents. / Graduate and Postdoctoral Studies / Graduate

The purpose of this project was to develop a spoken word-recognition task that could be used clinically to evaluate recognition performance of individuals with hearing loss in a background noise. The test instrument incorporated monosyllabic words at seven levels over a 35-dB range presented in a background of "multi-talker" babble that was fixed in level. In Experiment 1, we established normative data on 24 young adult listeners with normal hearing and on 50 older adult listeners with high-frequency hearing loss. In Experiment 2, we examined the effects that age and hearing loss have on understanding speech in multi-talker babble by studying 15 subjects in each decade interval from 20 to 79 years.

The development of perceptual-cognitive processes during infancy has been traditionally studied using visual habituation and paired-comparison techniques. There has been extensive work within the field of infant attention that has focused on the development of visual attention. Within this field, it has been well established that there are two distinct classifications of infants' visual behavior; infants with short visual fixations who perform well in a recognition task following familiarization and infants with long visual fixation with impaired performance. There are two hypotheses for the differences underlying these groups. First, that visual fixation duration is reflective of the speed of information processing such that long-looking infants process information more slowly than short-looking infants. The second hypothesis is that infants who are long-looking have difficulty disengaging and shifting their attention to another location. There has not been any work exploring how these differences manifest themselves in other modalities. Thus, this project has three purposes: (1) to explore whether group differences emerge in an auditory recognition task similar to those found in the visual recognition phase of the paired-comparison task, (2) to better understand how performance differences in the visual task correspond to any observed differences in an auditory task, and (3) to identify any potential mechanisms which may account for the observed differences in group performance on an auditory task. / Ph. D.

Orientadora: Ana Cláudia Vieira Cardoso / Banca: Michele Vargas Garcia / Banca: Cristiane Moço Canhetti de Oliveira / Resumo: Objetivo: Validar o conteúdo e o processo de aplicabilidade de um instrumento de avaliação do esforço auditivo para indivíduos com perda auditiva. Método: Trata-se de um estudo de validação, desenvolvido em três fases, sendo a Fase 1 o planejamento e desenvolvimento da primeira versão do instrumento para mensuração do esforço auditivo para indivíduos com perda auditiva; a Fase 2 a investigação das evidências de validade baseadas no conteúdo do instrumento para mensuração do esforço auditivo e; a Fase 3 a investigação das evidências de validade baseadas nos processos de resposta e desenvolvimento da versão final do instrumento para mensuração de esforço auditivo na população com perda auditiva. Participaram 10 profissionais com expertise na área de audiologia, com mais de cinco anos de experiência clínica. Cada participante fonoaudiólogo aplicou o instrumento para mensuração do esforço auditivo em pelo menos um indivíduo com perda de audição do tipo sensorioneural e grau de leve a moderado, classificados de acordo com a média quadritonal (500, 1000, 2000 e 4000Hz) e idade acima de 18 anos, de ambos os sexos. O instrumento a ser validado foi composto por três partes: I -"percepção de fala de logatomas e esforço auditivo"; II -"esforço auditivo e memória operacional" e; III - "percepção de sentenças sem sentido e memória operacional". As instruções e estímulos de fala do instrumento foram gravados a fim de evitar viés e as três partes do instrumento foram apresentadas de forma m... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Purpose: To validate the content and process of applicability of an instrument of the listening effort assessment for hearing impaired individuals. Method: This is a validation study, developed in three stages, with Stage 1 planning and development of the first version of the instrument for listening effort measurement for hearing impaired individuals; Stage 2 investigation of the evidences of validity based on the content of the instrument for the listening effort measurement and; Stage 3 investigation of the evidences of validity based on the response processes and development of the final version of the instrument of listening effort measurement in the population with hearing loss. A total of ten professionals with expertise in the field of audiology, with more than five years of clinical experience participated in this study. Each audiologist applied the instrument to measure the listening effort in at least one individual with mild to moderate sensorineural hearing loss, classified according to the quadritonal average (500, 1000, 2000 and 4000Hz) and age above 18 years old, of both sexes. The instrument to be validated was composed of three parts: I - "speech perception of logatomes and listening effort"; II - "listening effort and working memory" e; III - "speech perception of meaningless sentences and working memory". The instructions and speech stimuli of the instrument were recorded in order to avoid bias and the three parts of the instrument were monoaurally present... (Complete abstract click electronic access below) / Mestre

A fundamental task in reasoning is to form some internal representation of the premises that allows the relations between them to be determined. Whether this process is visual or auditory is the subject of a long-standing controversy. This controversy seems to have reached a stalemate. Another approach is to determine where in the brain reasoning is done. A way of doing this involves looking at differences in the processing and storage of visual and auditory information within the brain. Brooks used this approach in his experiments. His results suggested that a subject who receives spatial information by of the ear will, concurrent with reception, convert it into a visual representation. If, however, the individual receives a message in written form, be must use the visual system to both identify the words and, at the same time, represent the spatial relationships. Visually receive messages interfere with the generation of internal representations of spatial relations. Later experiments convinced Brooks that memories are stored in the system by which they enter the brain.

This study investigated the effects of stimulus type on the measurement s of short-term auditory memory span and short-term auditory memory for sequence to determine if span and sequence measures were the same within each of five subtests and if span and/or sequence measures varied across all five subtests. A total of forty-five normal second, third, and fourth grade subjects were individually administered the Auditory Memory Test Battery (AMTB) which consisted of five tape-recorded tests of recall for digit sequences, unrelated word sequences, related word sequences, nonsense word sequences, and sentences. The subjects responded verbally to the randomly presented subtests. Each subject obtained ten scores: a span score and a sequence score for each of the five subtests. The results of the study showed the span and sequence scores for the digit task differed significantly, with the span task being easier; however, the scores did not differ significantly for unrelated words, related words, nonsense words, or sentences. Both span and sequence performances were found to vary significantly with the type of stimulus; however, no difference was found in sequence performance between related and unrelated words. Generally, sentence recall was easier than recall of individual words, and recall of nonsense words was most difficult.

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Amplitude envelope is an important aspect of auditory perception. As one article included (Chapter 3) goes into great detail regarding this, it will not be discussed here. Included are two articles that explore the importance and influence of amplitude envelope in auditory perception research. The first article (Chapter 2) explores the role of amplitude envelope in an associative memory task, with the aim of improving the associability of auditory alarms in medical devices. Although we found no difference in performance based on amplitude envelope, the paper discusses the patterns of incorrect alarm identification and identifies potential sources of confusion. While this was not our initial goal, we feel this article is a valuable contribution that connects two distinct fields: music cognition and alarm design. The second article (Chapter 3) encompasses a meta-analysis, surveying the temporal structure of sounds used in auditory perception research, namely in the journal Attention, Perception & Psychophysics. This articles discusses several studies in which amplitude envelope has categorically influenced experimental outcomes and suggests that the standard ‘flat’ temporal structure (i.e. abrupt onset, period of sustain and abrupt offset) may not be the best way to evaluate the auditory system. The goal of this article is to determine what proportion of studies are using the standard ‘flat’ tones vs. other types of temporal structures we may encounter during everyday listening. These two articles collectively illustrate the original research I have completed on amplitude envelope during my Master’s Degree. / Thesis / Master of Science (MSc)

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