Matching Items (14)
Description
Two groups of cochlear implant (CI) listeners were tested for sound source localization and for speech recognition in complex listening environments. One group (n=11) wore bilateral CIs and, potentially, had access to interaural level difference (ILD) cues, but not interaural timing difference (ITD) cues. The second group (n=12) wore a single CI and had low-frequency, acoustic hearing in both the ear contralateral to the CI and in the implanted ear. These `hearing preservation' listeners, potentially, had access to ITD cues but not to ILD cues. At issue in this dissertation was the value of the two types of information about sound sources, ITDs and ILDs, for localization and for speech perception when speech and noise sources were separated in space. For Experiment 1, normal hearing (NH) listeners and the two groups of CI listeners were tested for sound source localization using a 13 loudspeaker array. For the NH listeners, the mean RMS error for localization was 7 degrees, for the bilateral CI listeners, 20 degrees, and for the hearing preservation listeners, 23 degrees. The scores for the two CI groups did not differ significantly. Thus, both CI groups showed equivalent, but poorer than normal, localization. This outcome using the filtered noise bands for the normal hearing listeners, suggests ILD and ITD cues can support equivalent levels of localization. For Experiment 2, the two groups of CI listeners were tested for speech recognition in noise when the noise sources and targets were spatially separated in a simulated `restaurant' environment and in two versions of a `cocktail party' environment. At issue was whether either CI group would show benefits from binaural hearing, i.e., better performance when the noise and targets were separated in space. Neither of the CI groups showed spatial release from masking. However, both groups showed a significant binaural advantage (a combination of squelch and summation), which also maintained separation of the target and noise, indicating the presence of some binaural processing or `unmasking' of speech in noise. Finally, localization ability in Experiment 1 was not correlated with binaural advantage in Experiment 2.
ContributorsLoiselle, Louise (Author) / Dorman, Michael F. (Thesis advisor) / Yost, William A. (Thesis advisor) / Azuma, Tamiko (Committee member) / Liss, Julie (Committee member) / Arizona State University (Publisher)
Created2013
Description
In the noise and commotion of daily life, people achieve effective communication partly because spoken messages are replete with redundant information. Listeners exploit available contextual, linguistic, phonemic, and prosodic cues to decipher degraded speech. When other cues are absent or ambiguous, phonemic and prosodic cues are particularly important because they help identify word boundaries, a process known as lexical segmentation. Individuals vary in the degree to which they rely on phonemic or prosodic cues for lexical segmentation in degraded conditions.
Deafened individuals who use a cochlear implant have diminished access to fine frequency information in the speech signal, and show resulting difficulty perceiving phonemic and prosodic cues. Auditory training on phonemic elements improves word recognition for some listeners. Little is known, however, about the potential benefits of prosodic training, or the degree to which individual differences in cue use affect outcomes.
The present study used simulated cochlear implant stimulation to examine the effects of phonemic and prosodic training on lexical segmentation. Participants completed targeted training with either phonemic or prosodic cues, and received passive exposure to the non-targeted cue. Results show that acuity to the targeted cue improved after training. In addition, both targeted attention and passive exposure to prosodic features led to increased use of these cues for lexical segmentation. Individual differences in degree and source of benefit point to the importance of personalizing clinical intervention to increase flexible use of a range of perceptual strategies for understanding speech.
Deafened individuals who use a cochlear implant have diminished access to fine frequency information in the speech signal, and show resulting difficulty perceiving phonemic and prosodic cues. Auditory training on phonemic elements improves word recognition for some listeners. Little is known, however, about the potential benefits of prosodic training, or the degree to which individual differences in cue use affect outcomes.
The present study used simulated cochlear implant stimulation to examine the effects of phonemic and prosodic training on lexical segmentation. Participants completed targeted training with either phonemic or prosodic cues, and received passive exposure to the non-targeted cue. Results show that acuity to the targeted cue improved after training. In addition, both targeted attention and passive exposure to prosodic features led to increased use of these cues for lexical segmentation. Individual differences in degree and source of benefit point to the importance of personalizing clinical intervention to increase flexible use of a range of perceptual strategies for understanding speech.
ContributorsHelms Tillery, Augusta Katherine (Author) / Liss, Julie M. (Thesis advisor) / Azuma, Tamiko (Committee member) / Brown, Christopher A. (Committee member) / Dorman, Michael F. (Committee member) / Utianski, Rene L. (Committee member) / Arizona State University (Publisher)
Created2015
Description
This study explores the psychophysical and neural processes associated with the perception of sounds as either pleasant or aversive. The underlying psychophysical theory is based on auditory scene analysis, the process through which listeners parse auditory signals into individual acoustic sources. The first experiment tests and confirms that a self-rated pleasantness continuum reliably exists for 20 various stimuli (r = .48). In addition, the pleasantness continuum correlated with the physical acoustic characteristics of consonance/dissonance (r = .78), which can facilitate auditory parsing processes. The second experiment uses an fMRI block design to test blood oxygen level dependent (BOLD) changes elicited by a subset of 5 exemplar stimuli chosen from Experiment 1 that are evenly distributed over the pleasantness continuum. Specifically, it tests and confirms that the pleasantness continuum produces systematic changes in brain activity for unpleasant acoustic stimuli beyond what occurs with pleasant auditory stimuli. Results revealed that the combination of two positively and two negatively valenced experimental sounds compared to one neutral baseline control elicited BOLD increases in the primary auditory cortex, specifically the bilateral superior temporal gyrus, and left dorsomedial prefrontal cortex; the latter being consistent with a frontal decision-making process common in identification tasks. The negatively-valenced stimuli yielded additional BOLD increases in the left insula, which typically indicates processing of visceral emotions. The positively-valenced stimuli did not yield any significant BOLD activation, consistent with consonant, harmonic stimuli being the prototypical acoustic pattern of auditory objects that is optimal for auditory scene analysis. Both the psychophysical findings of Experiment 1 and the neural processing findings of Experiment 2 support that consonance is an important dimension of sound that is processed in a manner that aids auditory parsing and functional representation of acoustic objects and was found to be a principal feature of pleasing auditory stimuli.
ContributorsPatten, Kristopher Jakob (Author) / Mcbeath, Michael K (Thesis advisor) / Baxter, Leslie C (Committee member) / Amazeen, Eric L (Committee member) / Dorman, Michael F. (Committee member) / Arizona State University (Publisher)
Created2014
Description
Often termed the "gold standard" in the differential diagnosis of dysarthria, the etiology-based Mayo Clinic classification approach has been used nearly exclusively by clinicians since the early 1970s. However, the current descriptive method results in a distinct overlap of perceptual features across various etiologies, thus limiting the clinical utility of such a system for differential diagnosis. Acoustic analysis may provide a more objective measure for improvement in overall reliability (Guerra & Lovely, 2003) of classification. The following paper investigates the potential use of a taxonomical approach to dysarthria. The purpose of this study was to identify a set of acoustic correlates of perceptual dimensions used to group similarly sounding speakers with dysarthria, irrespective of disease etiology. The present study utilized a free classification auditory perceptual task in order to identify a set of salient speech characteristics displayed by speakers with varying dysarthria types and perceived by listeners, which was then analyzed using multidimensional scaling (MDS), correlation analysis, and cluster analysis. In addition, discriminant function analysis (DFA) was conducted to establish the feasibility of using the dimensions underlying perceptual similarity in dysarthria to classify speakers into both listener-derived clusters and etiology-based categories. The following hypothesis was identified: Because of the presumed predictive link between the acoustic correlates and listener-derived clusters, the DFA classification results should resemble the perceptual clusters more closely than the etiology-based (Mayo System) classifications. Results of the present investigation's MDS revealed three dimensions, which were significantly correlated with 1) metrics capturing rate and rhythm, 2) intelligibility, and 3) all of the long-term average spectrum metrics in the 8000 Hz band, which has been linked to degree of phonemic distinctiveness (Utianski et al., February 2012). A qualitative examination of listener notes supported the MDS and correlation results, with listeners overwhelmingly making reference to speaking rate/rhythm, intelligibility, and articulatory precision while participating in the free classification task. Additionally, acoustic correlates revealed by the MDS and subjected to DFA indeed predicted listener group classification. These results beget acoustic measurement as representative of listener perception, and represent the first phase in supporting the use of a perceptually relevant taxonomy of dysarthria.
ContributorsNorton, Rebecca (Author) / Liss, Julie (Thesis advisor) / Azuma, Tamiko (Committee member) / Ingram, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Distorted vowel production is a hallmark characteristic of dysarthric speech, irrespective of the underlying neurological condition or dysarthria diagnosis. A variety of acoustic metrics have been used to study the nature of vowel production deficits in dysarthria; however, not all demonstrate sensitivity to the exhibited deficits. Less attention has been paid to quantifying the vowel production deficits associated with the specific dysarthrias. Attempts to characterize the relationship between naturally degraded vowel production in dysarthria with overall intelligibility have met with mixed results, leading some to question the nature of this relationship. It has been suggested that aberrant vowel acoustics may be an index of overall severity of the impairment and not an "integral component" of the intelligibility deficit. A limitation of previous work detailing perceptual consequences of disordered vowel acoustics is that overall intelligibility, not vowel identification accuracy, has been the perceptual measure of interest. A series of three experiments were conducted to address the problems outlined herein. The goals of the first experiment were to identify subsets of vowel metrics that reliably distinguish speakers with dysarthria from non-disordered speakers and differentiate the dysarthria subtypes. Vowel metrics that capture vowel centralization and reduced spectral distinctiveness among vowels differentiated dysarthric from non-disordered speakers. Vowel metrics generally failed to differentiate speakers according to their dysarthria diagnosis. The second and third experiments were conducted to evaluate the relationship between degraded vowel acoustics and the resulting percept. In the second experiment, correlation and regression analyses revealed vowel metrics that capture vowel centralization and distinctiveness and movement of the second formant frequency were most predictive of vowel identification accuracy and overall intelligibility. The third experiment was conducted to evaluate the extent to which the nature of the acoustic degradation predicts the resulting percept. Results suggest distinctive vowel tokens are better identified and, likewise, better-identified tokens are more distinctive. Further, an above-chance level agreement between nature of vowel misclassification and misidentification errors was demonstrated for all vowels, suggesting degraded vowel acoustics are not merely an index of severity in dysarthria, but rather are an integral component of the resultant intelligibility disorder.
ContributorsLansford, Kaitlin L (Author) / Liss, Julie M (Thesis advisor) / Dorman, Michael F. (Committee member) / Azuma, Tamiko (Committee member) / Lotto, Andrew J (Committee member) / Arizona State University (Publisher)
Created2012
Description
Spanish-speaking (SS) dual language learners (DLLs) have shown differential developmental profiles of the native language (L1). The current study examined whether or not the Spanish acquisition profile, specifically accusative clitics, in predominantly SS, Latino children continues to develop in an English-language contact situation. This study examined (1) accuracy rates of clitic production, total substitutions, and total omissions across 5-, 6-, and 7-year-olds; (2) accuracy rates of clitic production, total substitutions, and total omissions across low and high English proficiency groups; and (3) whether or not there was a trend to use the default clitic lo in inappropriate contexts. Seventy-four SS children aged 5;1 to 7;11 participated in a clitic elicitation task. Results indicated non-significant effects of age and proficiency level on the accuracy of clitic production. These results suggest dual language learners are in an environment that does not foster the maintenance of the L1, at least in the accuracy of accusative clitic pronouns.
ContributorsFigueroa, Megan Danielle (Author) / Restrepo, María A (Thesis advisor) / Gelderen, Elly van (Committee member) / Ingram, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Minimal information exists concerning dual language acquisition of three-year-old dual language learners (DLLs) during their first school experience and first systematic exposure to English. This study examined the Spanish and early English language development of young DLLs in the context of standardized measures and a story retell task. Participants included eight Spanish-English DLLs (7 females, 1 male, M age = 3 years, 8 months) attending Head Start, and their classroom teachers. Outcome measures for the children included composite and scaled scores on the Clinical Evaluation of Language Fundamentals Preschool-2 Spanish (CELF Preschool-2 Spanish; Wiig, Secord & Semel, 2009) and the parallel English measure (CELF Preschool-2; Wiig, Secord & Semel, 2005), and measures of lexical (NVT, NNVT, TNV, NW, NDW, TNW and TTR) and grammatical (MLUw) development. Proportion of classroom teachers' and paraprofessionals' Spanish, English and mixed language use was measured to contextualize the children's learning environment with regard to language exposure. Children's mean standardized Spanish scores at school entry were not significantly different from their mean scores in May; however, an increase in total number of verb types was observed. Children's English receptive, content, and structure mean standardized scores in May were significantly higher than their scores at school entry. Children were exposed to a high proportion of mixed language use and disproportionate amounts of English and Spanish exclusively. Children's performance was highly variable across measures and languages. The findings of the current study provide a reference point for future research regarding language development of three-year-old Spanish-English dual language learners.
ContributorsDubasik, Virginia L (Author) / Wilcox, M J (Thesis advisor) / Ingram, David (Committee member) / Lafferty, Addie (Committee member) / Macswan, Jeff (Committee member) / Arizona State University (Publisher)
Created2011
Description
Purpose: The present study examined grammatical gender use in child Spanish heritage speakers (HSs) in order to determine whether the differences observed in their grammar, when compared to Spanish monolinguals, stem from an incompletely acquired grammar, in which development stops, or from a restructuring process, in which features from the dominant and the weaker language converge to form a new grammatical system. In addition, this study evaluated whether the differences usually found in comprehension are also present in production. Finally, this study evaluates if HSs differences are the result of the input available to them.
Method: One-hundred and four typically developing children, 48 HSs and 58 monolingual, were selected based on two age groups (Preschool vs. 3rd Grade). Two comprehension and three production experimental tasks were designed for the three different grammatical structures where Spanish expresses gender (determiners, adjectives, and clitic pronouns). Linear mixed-models were used to examine main effects between groups and grammatical structures.
Results: Results from this study showed that HSs scored significantly lower than monolingual speakers in all tasks and structures; however, 3rd-Grade HSs had higher accuracy than PK-HSs. Error patterns were similar between monolinguals and HSs. Moreover, the commonly reported overgeneralization of the masculine form seems to decrease as HSs get older.
Conclusion: These results suggest that HSs’ do not face a case of Incomplete Acquisition or Restructured Grammatical gender system, but instead follow a protracted language development in which grammatical skills continue to develop after preschool years and follow the same developmental patterns as monolingual children
Method: One-hundred and four typically developing children, 48 HSs and 58 monolingual, were selected based on two age groups (Preschool vs. 3rd Grade). Two comprehension and three production experimental tasks were designed for the three different grammatical structures where Spanish expresses gender (determiners, adjectives, and clitic pronouns). Linear mixed-models were used to examine main effects between groups and grammatical structures.
Results: Results from this study showed that HSs scored significantly lower than monolingual speakers in all tasks and structures; however, 3rd-Grade HSs had higher accuracy than PK-HSs. Error patterns were similar between monolinguals and HSs. Moreover, the commonly reported overgeneralization of the masculine form seems to decrease as HSs get older.
Conclusion: These results suggest that HSs’ do not face a case of Incomplete Acquisition or Restructured Grammatical gender system, but instead follow a protracted language development in which grammatical skills continue to develop after preschool years and follow the same developmental patterns as monolingual children
ContributorsMartinez-Nieto, Lourdes (Author) / Restrepo, Maria Adelaida (Thesis advisor) / Renaud, Claire (Thesis advisor) / Pascual y Cabo, Diego (Committee member) / Thompson, Marilyn (Committee member) / Ingram, David (Committee member) / Arizona State University (Publisher)
Created2018
Description
This thesis compared two measures of phonological assessment of children, Shriberg and Kwiatkowski's 1980 Percentage of Correct Consonants (PCC) and Ingram's 2002 Proportion of Whole Word Proximity (PWP). Two typically developing two-year-old children were initially studied, and then nine children with speech sound disorders. The children's words were divided into four categories ranging from least complex to most complex. It was hypothesized that the measures would correlate with word simplicity. The hypothesis was supported for the two typically developing children, and for five of the children with speech sound disorders. The other four children with speech disorders, however, did not show the correlation. It was concluded that PCC and PWP did not measure the same thing, that PCC alone was sufficient to assess the typically developing children, and that the two measures together better captured the ability of the children with speech sound disorders than either singularly. Further, the differences between the two groups of children with speech sound disorders were interpreted as showing a difference between phonological delay and phonological disorder.
ContributorsKnodel, Rebekah Katelyn (Author) / Ingram, David (Thesis director) / Major, Roy (Committee member) / Fox, Angela (Committee member) / Barrett, The Honors College (Contributor) / Department of Speech and Hearing Science (Contributor)
Created2013-05
Description
This thesis investigated the impact of word complexity as measured through the Proportion of Whole Word Proximity (PWP; Ingram 2002) on consonant correctness as measured by the Percentage of Correct Consonants (PCC; Shriberg & Kwiatkowski 1980) on the spoken words of monolingual Spanish-speaking children. The effect of word complexity on consonant correctness has previously been studied on English-speaking children (Knodel 2012); the present study extends this line of research to determine if it can be appropriately applied to Spanish. Language samples from a previous study were used (Hase, 2010) in which Spanish-speaking children were given two articulation assessments: Evaluación fonológica del habla infantil (FON; Bosch Galceran, 2004), and the Spanish Test of Articulation for Children Under Three Years of Age (STAR; Bunta, 2002). It was hypothesized that word complexity would affect a Spanish-speaking child’s productions of correct consonants as was seen for the English- speaking children studied. This hypothesis was supported for 10 out of the 14 children. The pattern of word complexity found for Spanish was as follows: CVCV > CVCVC, Tri-syllables no clusters > Disyllable words with clusters.
ContributorsPurinton, Kaitlyn Lisa (Author) / Ingram, David (Thesis director) / Dixon, Dixon (Committee member) / Barlow, Jessica (Committee member) / Barrett, The Honors College (Contributor) / Department of Speech and Hearing Science (Contributor) / School of International Letters and Cultures (Contributor)
Created2013-12