Browsing by Subject "Intelligibility"

Now showing 1 - 7 of 7

Effects of intelligibility on within- and cross-modal sentence recognition memory for native and non-native listeners
(2018-05) Keerstock, Sandie; Smiljanic, Rajka, 1967-
The goal of the study was to examine whether the enhanced clarity of the speech signal, namely a listener-oriented clear speech, improves sentence recognition memory for native and non-native listeners, and whether this effect would hold across modality of presentation. The results showed that listener-oriented clear speech enhanced sentence recognition memory for both listener groups regardless of whether the acoustic signal is present during the test phase (Experiment I) or absent (Experiment II). Compared to native listeners, non-native listeners had longer reaction times in the within-modal task and were overall less accurate in the cross-modal task. The results showed that more cognitive resources remained available for storing information in memory during processing of easier-to-understand clearly produced sentences. Furthermore, second language processing additionally depleted cognitive resources needed for remembering speech information
Environment- and listener-oriented speaking style adaptations across the lifespan
(2014-08) Gilbert, Rachael Celia; Smiljanic, Rajka, 1967-
This dissertation examines how age affects the ability to produce intelligibility- enhancing speaking style adaptations in response to environment-related difficulties (noise-adapted speech) and in response to listeners’ perceptual difficulties (clear speech). Materials consisted of conversational and clear speech sentences produced in quiet and in response to noise by children (11-13 years), young adults (18-29 years), and older adults (60-84 years). Acoustic measures of global, segmental, and voice characteristics were obtained. Young adult listeners participated in word-recognition-in-noise and perceived age tasks. The study also examined relative talker intelligibility as well as the relationship between the acoustic measurements and intelligibility results. Several age-related differences in speaking style adaptation strategies were found. Children increased mean F0 and F1 more than adults in response to noise, and exhibited greater changes to voice quality when producing clear speech (increased HNR, decreased shimmer). Older adults lengthened pause duration more in clear speech compared to younger talkers. Word recognition in noise results revealed no age-related differences in the intelligibility of conversational speech. Noise-adapted and clear speech modifications increased intelligibility for all talker groups. However, the acoustic changes implemented by children when producing noise-adapted and clear speech were less efficient in enhancing intelligibility compared to the young adult talkers. Children were also less intelligible than older adults for speech produced in quiet. Results confirmed that the talkers formed 3 perceptually-distinct age groups. Correlation analyses revealed that relative talker intelligibility was consistent for conversational and clear speech in quiet. However, relative talker intelligibility was found to be more variable with the inclusion of additional speaking style adaptations. 1-3 kHz energy, speaking rate, vowel and pause durations all emerged as significant acoustic-phonetic predictors of intelligibility. This is the first study to investigate how clear speech and noise-adapted speech benefits interact with each other across multiple talker groups. The findings enhance our understanding of intelligibility variation across the lifespan and have implications for a number of applied realms, from audiologic rehabilitation to speech synthesis.
Improving the speech intelligibility of adults with Down syndrome (DS) using the core vocabulary approach
(2016-05) Easter, Michelle Lee; Davis, Barbara L. (Barbara Lockett); Franco, Jessica Hetlinger
The goal of the present study was to evaluate the efficacy of the Core Vocabulary approach (CVA; Dodd, Holm, Crosbie, & McIntosh, 2006) for improving speech intelligibility in an adult with DS by establishing consistent word production in order to enhance communicative competence and participation within a variety of social settings. Research indicates marked limitations in speech intelligibility in individuals with DS, including delayed and disordered articulation and inconsistent speech errors (i.e., variability in production of the same word) that continues throughout the individual’s life (Kent & Vorperian, 2013). This study evaluated the effectiveness of CVA on intelligibility by targeting reduction in variability in target word productions selected because they were functionally salient for the client. Data collection consisted of a slight adaptation to CVA, including both speech accuracy and variability measures to evaluate the effect of CVA. The following question was addressed: What are the effects of core vocabulary on the variability and accuracy of production of target words in an adult with DS? Results suggest that vowel accuracy is a relative strength in her system as compared to consonants, and two-syllable shaped words are her upper boundary. However, while accuracy measures demonstrated some slight improvement across intervention sessions, variability remained stable and did not show the same change over time. A variety of adaptations and possible future research topics are discussed.
Making sense of speech : a practical approach to pronunciation assessment
(2014-12) Kroman, Steven Andrew; Garza, Thomas J.
Recent research has shifted the focus of pronunciation instruction from achieving native-like speech in learners to correcting issues that affect the intelligibility of the learners’ speech. Research also suggests that suprasegmental features of pronunciation, such as intonation, rhythm, and stress, have a considerable influence on intelligibility. By using Dickerson’s (1989) Covert Rehearsal Model, which includes predictive strategies that encourage learner autonomy, instructors have the tools necessary to effectively help learners improve their intelligibility. However, the question as to which instructional targets should be taught in the classroom still remains. This report outlines one way in which instructors can use a diagnostic assessment in order to discover which instructional targets are most appropriate for their learners.
Memory for speech of varying intelligibility : effects of perception and production of clear speech on recall and recognition memory for native and non-native listeners and talkers
(2020-07-15) Keerstock, Sandie; Smiljanic, Rajka, 1967-; Myers, Scott P; Crowhurst, Megan; Quinto-Pozos, David; Shafiro, Valeriy
This dissertation examines the effects of signal-related articulatory-acoustic enhancements in the form of clear speech on signal-independent processes and integration of information in memory. In a series of five experimental studies, this dissertation investigates the effect of clear speech production and perception on recognition memory and recall for native and non-native listeners and talkers. Two perception studies in Chapter 2 examined the effect of clear speech on within-modal (i.e., audio-audio) or cross-modal (i.e., audio-text) sentence recognition memory for native and non-native listeners. A perception study in Chapter 3 tested the effect of clear speech on recall, a more complex memory task, for native and non-native listeners. Finally, two production studies in Chapter 4 investigated the effect of producing clear speech on recognition memory and recall for native and non-native talkers. Key findings from this dissertation were that clear speech improved within- and cross-modal recognition memory and recall for native and non-native listeners but impaired recognition memory and recall for native and non-native talkers. These seemingly disparate findings in perception and production are discussed in the light of the models that appeal to ‘effort’ and cognitive load as detrimental to memory. This dissertation provides novel theoretical insights into how lower-level acoustic-phonetic enhancements interact with higher-level memory processes in first and second-language speech perception and production. The results from this dissertation have practical implications in a variety of environments where retention of spoken information is essential, such as classrooms and hospitals.
Speech production outcomes in young children with early identified hearing loss
(2018-06-15) Yi, Hoyoung; Byrd, Courtney T.; Davis, Barbara L. (Barbara Lockett); Champlin, Craig; Smiljanic, Rajka; Campbell, Julia; Sundarrajan, Madhu
Relevant acoustic and linguistic information is not accessible to young children with a damaged or absent sense of hearing. While infant hearing screening enables early instrumentation and intervention for children with hearing loss, they have shown a substantial amount of variability in speech production outcomes. Comprehensive analysis of speech outcomes using contemporary speech and language measures is pivotal to specifying the diversity of speech characteristics in addition to understanding the relationship of auditory input system and production output system capacities. Speech characteristics in spontaneous speech output of children with hearing loss were examined by analyzing associations across multiple speech and language measures, relationships of speech accuracy with input factors of phonotactic probability and neighborhood density, and speech intelligibility as perceived by adult listeners. Spontaneous connected speech samples were collected for twenty-one children with bilateral cochlear implants or hearing aids. Results revealed a largely consistent chronological age-related developmental pattern across the speech measures and mean length of utterance (MLU). Most of the children demonstrated a delay in acquiring later developing consonants and more complex word forms. Based on individual variance in performance across analysis measures, environmental factors contributing to individual differences in their speech production include chronological age at receiving instrumentation and familiarity of the speech sampling context. Phonotactic probability and neighborhood density showed positive relationships with consonant accuracy in CVC word forms produced. Vowel accuracy in CVC word forms was negatively related to neighborhood density in this cohort. Intelligibility outcomes were highly associated with speech measures, suggesting the importance of a whole-word analysis approach. These results emphasize the importance of analyzing functional daily communication interactions in children fit early with HA or CI instrumentation. Findings support use of measures that can reveal the sources of reduced intelligibility.
Teaching suprasegmentals through strategy use and technology
(2014-12) Noble, Emily Marie; Horwitz, Elaine Kolker, 1950-
In an increasingly global world, there is a growing demand for pronunciation instruction. A focus on intelligibility as the goal in pronunciation instruction has risen to the forefront of the literature. Suprasegmentals are a practical goal for instruction since they have been shown to have a greater impact on overall intelligibility, but many language curricula do not allocate time or resources to pronunciation instruction at all, making it difficult for teachers to incorporate much needed suprasegmental learning in language classrooms. This Report suggests a practical way to incorporate suprasegmental learning in a mixed language background classroom: a project that incorporates a Web 2.0 tool, VoiceThread, and Covert Rehearsal Model strategy use.