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Thesis (Ph. D.)--State University of New York at Binghamton, Anthropology Dept., 2006. / Includes bibliographical references.

The relationship between language and reading has been studied from several perspectives but is not fully understood. Studies of this relationship have examined the relative importance of decoding and basic reading skills versus broader language skills for reading comprehension, reporting that phonological awareness and decoding are more important for reading comprehension early in the process of literacy acquisition, whereas broader language skills become more important with decoding proficiency (e.g., Curtis, 1980; Perfetti, 1985; Vellutino, Scanlon, Small, & Tanzman, 1991). This study sought to explore these relationships in the context of Woodcock Johnson III Tests of Achievement (Woodcock, McGrew, & Mather, 2001), a single test battery that includes measures of each of these areas. A repeated multiple regression approach (as used in McGrew, 1993) in which Reading Fluency cluster and Reading Comprehension cluster served as criteria and Sound Awareness test, Basic Reading cluster, Listening Comprehension cluster, and Oral Expression cluster served as predictors was used to examine these issues. These analyses were computed for six age groups (age 6, 7, 8-9, 10-12, 13-16, and 17-18; n = 2,885) and six grade groups (grade 1, 2, 3, 4-6, 7-9, and 10-12; n = 2,748) in a cross-sectional design to allow for consideration of relationships across the school years. Standardized regression coefficients were utilized as measures of relative importance, and were plotted to reveal trends in these relationships. The results indicated that the strength of the relationships of Reading Fluency and Reading Comprehension with Basic Reading (particularly Letter-Word Identification) decreased across age and grade groups. This decrease was accompanied by an increased association between Reading Fluency and Listening Comprehension across age and grade groups, and an increased association of all predictors other than Basic Reading with Reading Comprehension across age and grade groups. These findings support those of previous studies, as well as the hypothesis that broader language skills become more strongly associated with reading comprehension as decoding proficiency increases.

This project investigated speech recognition in rooms of different size with similar average reverberation times. A comparative analysis of existing literature has provided evidence to support that speech recognition in small rooms may be poorer than in larger rooms when the two spaces have a similar amount of reverberation. This study evaluated speech recognition using sentences binaurally recorded using an acoustic manikin in three rooms of different volume and/or dimension. The three rooms included a small reverberation chamber (48 m3), a university lecture hall (479 m3), and a high school band practice room (474 m3). Speech recognition was tested using bilateral insert earphones in two groups with 13 participants in each group. One group consisted of individuals with normal-hearing and the second group consisted of participants with mild-to-severe hearing impairment. Testing was completed at five signal-to-noise ratios (SNRs) for each group. Several measures, designed to quantify the acoustic characteristics of each room, were made and included mean free path, frequency-specific reverberation time and the Speech Transmission Index (STI). This investigation determined that listeners in both groups showed a significant decrease in speech recognition performance as SNRs decreased and a significant effect of room size. The poorest speech recognition was measured in the smallest room. There was no interaction between SNR and room type for either of the two participant groups. The effect of both change in room size and SNR correlated well with changes in Speech Transmission Index. A rationale was proposed as the source of the room size-specific reverberation effects. This idea speculates that the period during which early reflections are beneficial to speech understanding may decrease as room size increases. This is consistent with measures of decreased mean free path in smaller rooms. In addition, the reverberant field of a small room will contain more reflections than a larger room when the two are matched for reverberation time. It is proposed that the increased number of overlapping reflections also contributes to decreases in speech recognition ability.

The goal of this study was to examine word learning in preschool children with low socioeconomic status (SES) to inform an understanding of the limited word knowledge of this population. There is evidence to suggest that impoverished linguistic input explains substantial variability in word knowledge of children with low SES. Research has not yet considered the ways that children with low SES make use of linguistic input. Participants, preschool children with low SES, completed a part-term fast-mapping task. Specific cues of a familiar whole object, possessive syntax, and whole-part juxtaposition were provided to children in linguistic input using standard verbal scripts. As a group, participants provided more part-term responses when provided with cues than when no cues were presented. Participants provided the most part-term responses when multiple cues were presented in combination. Thus, children with low SES appear to use word learning strategies to make use of information in the linguistic input, similar to peers with higher SES. Participants with limited word knowledge, as defined by performance on a norm-referenced measure, were less accurate on the part-term task than peers with age-appropriate word knowledge. This finding suggests that children with low SES and limited word knowledge are inefficient word learners.

ASSESSMENT OF A MEASURE OF RESPONSE CONFIDENCE FOR A SPEECH RECOGNITION TASK IN NOISE <p> JOHN ANDREW DUNDAS <p> Dissertation under the direction of Gary P Jacobson, Ph.D. <p> The development of a measure of response confidence for a speech understanding task is presented in this dissertation. Normal hearing participants completed speech understanding tasks in background noise and rated confidence in their responses. In experiment 1, the relationships between measured performance, perceived performance and confidence in the correctness of responses were investigated. In experiment 2, the effect of sentence context on response confidence was investigated. The main findings of this study are; 1. Confidence ratings of speech intelligibility performance can be consistently measured using simple tools, 2. Confidence ratings are strongly correlated with measured performance, 3. Confidence ratings are highly repeatable, 4. Sentence based test materials with a high degree of context result in the most accurate calibration to measured performance, and, 5. Low context sentences result in a faster growth of confidence (i.e., overconfidence). These findings suggest that confidence ratings could be a useful outcome measure in the evaluation of treatment efficacy in the hearing impaired population.

The purpose of this project is to define for young, middle age, and elderly subjects the best frequency(cies) to record both the cVEMP and the oVEMP. An additional objective of this study is to describe the age related changes in the frequency tuning of both the cVEMP and oVEMP. Our hypothesis is that damage to the saccule or utricle, as a result of aging, would alter the resonant frequency of the end organ thus altering the frequency tuning characteristics of the vestibular system. Our results show that there are no significant differences in VEMP amplitude evoked by a 500 Hz, 750 Hz, and 1000 Hz air conduction tone bursts for our subjects. Our findings also show that aging results in an overall flattening or loss of frequency tuning in older adults for the cVEMP, but not the oVEMP. Additionally, the frequency tuning of both the cVEMP and oVEMP shifts to a higher frequency in the older adult group compared to the middle age and young adult groups. Accordingly, for dizzy patients over the age of 60 years, a 500 Hz air conduction tone burst may not be the ideal frequency to elicit a VEMP response. We recommend using a stimulus frequency of 750 Hz or 1000 Hz in this population.

This thesis is concerned with auditory motion perception and the combinations of cues that contribute to human sensitivity of signals that change in spatial position. Measurement of how sensitive individuals are to the rates of change for auditory cues are difficult because of confounds between duration, extent, and velocity of the changing signal. Dooley and Moore (1988) proposed a psychometric tool for measuring sensitivity to rate of auditory cue change using a duration discrimination task. They reported that duration discrimination was improved when an additional cue based on rate of change (of intensity or frequency) was present. This provided a back door approach to measuring sensitivity to rate of change. The current experiments were designed to measure sensitivity to the rate of change in intensity and spatial position. Experiment 1 investigated whether performance was enhanced in a duration discrimination task when additional cues consisting of rate of intensity change (partial replication of Dooley and Moore, 1988), rate of spatial position change, or both cues were provided. Duration discrimination was not enhanced by these cues, in fact, it was worse. Experiment 2 assessed whether duration discrimination could be used to measure sensitivity to rates of changes in intensity and motion if the rate differences were larger. As in Experiment 1, duration discrimination was not improved, and tended to worsen, when the velocity cues were present. Experiment 3 shifted the focus to a direct velocity discrimination task to determine whether sensitivity to rates of spatial change varied with the mix of directional and distance information that specified velocity. Performance was better when both directional and distance cues were provided, compared to conditions where only one of these cues was available. Moreover, the benefit from having both types of information was significantly better when direction and distance cues were weighted to be perceptually equal for each participant.

Binaural hearing results in a number of listening advantages relative to monaural hearing, including enhanced hearing sensitivity and better speech understanding in adverse listening conditions. These advantages are facilitated by the ability to detect and utilize interaural cues within the central auditory system. It is well understood that infants and children with Down syndrome have unique auditory structures resulting from congenital and acquired influences (e.g., Balkany, Mischke, Downs, & Jafek, 1979; Becker, Armstrong, & Chan, 1986; Bilgin, Kasemsuwan, Schachern, Paparella, & Le, 1996; Blaser, et al., 2006). Structural anomalies within the central auditory system and alterations in synaptic communication could adversely affect binaural hearing. However, binaural hearing capabilities have not been examined in these children. This study was designed to determine if the binaural abilities of children with Down syndrome are compromised relative to those of typically-developing children on a masking level difference task and a binaural intelligibility level difference task. Participants included typically-developing children aged 3 to 13 years (N=46) and children with Down syndrome aged 6 to 16 years (N=11). In addition, typically-developing adults (N=6) and adults with Down syndrome (N=3) were included to obtain an estimate of adult performance for the experimental tasks. Despite normal hearing sensitivity children with Down syndrome in this study had higher masked thresholds for our experimental stimuli and exhibited less release from masking than typically-developing children. These observations suggest that children with Down syndrome have similar speech recognition in noise as typically-developing children aged 3 to 5 years. The binaural advantages afforded to typically-developing children, such as enhanced hearing sensitivity and better speech understanding in adverse listening conditions, were not present for children with Down syndrome in this study. The reduced binaural benefit experienced by children with Down syndrome suggests that they will require more favorable signal-to-noise ratios than typically-developing children to achieve optimal performance in adverse listening conditions. This has important implications for the planning of educational and therapeutic interventions for individuals with Down syndrome.

This project is concerned with the relationship between type-1 diabetes and auditory pathology. In this dissertation I compared hearing sensitivity, cochlear function, and peripheral auditory neural function (afferent and efferent) in young adults with type-1 diabetes in comparison to matched controls. As a secondary objective I explored the influence of covariates, such as diabetes control, sex, and noise exposure. My findings suggest that the persons with type-1 diabetes demonstrated early signs of cochlear pathology and that this damage was related to sex and history of noise exposure. In addition, I demonstrated the utility of low-level stimulus evoked otoacoustic emissions in showing reduced cochlear function in participants with higher noise exposure and type-1 diabetes despite otherwise normal auditory function outcomes. Identification and recognition of early indices of cochlear pathology may allow intervention and prevention of noise related hearing loss in persons with and without type-1 diabetes.