Dissertations / Theses on the topic 'Speech reception threshold'

The use of speech audiometry is essential in audiological testing. One of the most important elements of speech audiometry is speech reception threshold. To provide services for the growing population of non-English speaking people, audiologists need speech audiometry materials in a variety of languages. The purpose of this study was to develop, digitally record, evaluate, and equate Arabic bisyllabic words for use in testing speech reception threshold. Ninety frequently used bisyllabic words were digitally recorded by a male talker of standard Arabic. These words were presented to 20 normally hearing subjects in 2 dB increments at intensity levels ranging from -10 to 22 dB HL. Psychometric functions were then determined for all 90 words using logistic regression. Words with steep psychometric functions were selected for inclusion in the test CD. The intensities of these selected words were adjusted to match the mean subject PTA within 2 dB, and a list of words was developed which was homogenous with respect to slope and audibility. The words are contained on tracks 2 and 3 of the Brigham Young University Arabic Speech Audiometry Materials (Disc 1.0) CD.

Digits-in-noise (DIN) tests have become very popular over the past 15 years for hearing loss detection. Several recent studies have highlighted the potential utility of digits-in-noise (DIN) as a school-aged hearing test. However, age may influence test performance in children. In addition, a new antiphasic stimulus paradigm has been introduced. This study determined the maturation of speech recognition for diotic and antiphasic DIN in children and evaluated DIN self-testing in young children. A cross-sectional, quantitative, quasi-experimental research design was used in this study. Participants with confirmed normal hearing were tested with diotic and antiphasic DIN test. During the DIN test, arrangements of three spoken digits were presented in noise via headphones at varying signal-to-noise ratios (SNRs). The researcher entered each three-digit sequence the participant said on a smartphone keypad. Six hundred and twenty-one normal hearing (bilateral pure tone threshold of ≤ 20 dB HL at 1, 2, and 4kHz) children between the ages of 6-13 years with normal hearing were recruited in order to examine the comparative maturation of diotic and antiphasic performance. A further sample of 30 first grade (7-year-old) children with normal hearing were recruited to determine the validity of self-testing on a smartphone. Multiple regression analysis including age, gender, and English additional language (i.e. Person whose first language or home language is not English) showed only age to be a significant predictor for both diotic and antiphasic SRT (p < 0.05). Speech reception thresholds improved by 0.15 dB and 0.35 dB SNR per year for diotic and antiphasic SRT, respectively. Post hoc multiple age group comparisons using Bonferroni adjustment for multiple comparisons (by year) showed SRTs for young children (6 to 9 years old) differed significantly from older children (11 to 13 years old) (p < 0.05). There was no significant difference in SRT between age 10 and upward. Self- and facilitated testing in young children was significantly (p > 0.05) different for the antiphasic condition and demonstrated poor reliability in diotic and antiphasic conditions. Increasing age was significantly associated with improved SRT using diotic and antiphasic DIN. Beyond 10 years of age, SRT results of children became more adult-like. However, age effects were only significant up to 10 and 12 years for antiphasic and diotic SRT, respectively. Furthermore, between self- and facilitated testing, the SRT difference was not significant (p > 0.05).
Dissertation (MA)--University of Pretoria, 2019.
Speech-Language Pathology and Audiology
MA
Unrestricted

In addition to the use of pure-tones for testing hearing, speech signals are highly valuable diagnostic tools for identifying and evaluating hearing impairment. Speech audiometry involves the implementation of such signals in the measurement of hearing acuity. One aspect of speech audiometry involves assessment of the speech recognition threshold (SRT) which evaluates an individual's ability to hear and understand speech. While live speech has been used in the past to assess SRT, recorded materials are preferred and have been shown to be advantageous over live speech. High-quality digitally recorded speech audiometry materials have been available in English for some time, but assessment of individuals using speech materials from a language that they do not speak natively has been shown to be both inadequate and inaccurate. Speech audiometry materials have recently become available in many languages. Currently, however, there are no known published recordings for assessment of SRT in the Tagalog language. The goal of this study was to develop psychometrically equivalent speech audiometry materials for measuring speech recognition threshold in Tagalog. During this study Tagalog words were initially recorded by a native speaker selected for accent and vocal quality. The words were reduced down to 90 words to be evaluated in the study. Each of the 90 trisyllabic words were evaluated at 2 dB increments from -10 to 16 dB HL by 20 native Tagalog speakers, all having normal hearing. Based on the results, 34 trisyllabic Tagalog words were selected based on their familiarity to native listeners, relative homogeneity with regards to audibility and psychometric function slope. Each word was then adjusted to make the 50% performance threshold equal to the mean PTA of the 20 research participants (4.3 dB HL). The final edited words were then digitally recorded onto compact disc for distribution and for use in assessing SRT in native Tagalog speakers worldwide.

Children with central auditory processing disorders (CAPD) have a normal pure-tone audiogram, however, they have difficulty understanding speech in the presence of background noise. The present study examined binaural hearing in normal children and those with possible CAPD. Each subject was administered the SCAN or SCAN-A, screening tests for CAPD, to determine whether they were at risk for CAPD. Participants were then subjected to several monaural and binaural speech tasks, in quiet and noise. Spondee words were utilized in each task, under headphone and soundfield conditions.

Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2004.
Includes bibliographical references (p. 191-203).
The importance of the cochlear active mechanism in the reception of speech in different types of noise was explored. The perceptual effects of loudness recruitment, a consequence of loss of the active mechanism, were assessed in simulated-loss listeners using a multiband expansion algorithm that models abnormal cochlear linearity. While this algorithm, which derives the expansion characteristic from absolute hearing thresholds, can accurately simulate the mean speech intelligibility results of hearing-impaired listeners, its ability to simulate the performance of individual listeners is limited. Given the relationship between loudness perception and the active mechanism, deriving the expansion characteristic from estimates of cochlear compression should provide a more accurate model of an individual listener's impairment. Towards this aim, the reliability of two psychoacoustic methods used to estimate the magnitude of compression (growth of masking and temporal masking) was assessed. Results suggest that growth of masking is a more reliable measure of compression in listeners with both normal and impaired hearing. The relationship between the compressive characteristics of the auditory system and speech perception in complex acoustic backgrounds was also evaluated. The operational status of the active mechanism was assessed behaviorally using three independently derived measures: (1) slope ratio of off- and on-frequency growth of masking functions, (2) equivalent rectangular bandwidth of auditory filters, and (3) masker-phase masking differences. These measures were correlated with speech reception thresholds (SRTs) in backgrounds with and without spectral and/or temporal-modulations. The relationship between slope ratios, filter bandwidths, and the maximum
(cont.) SRT difference (SRT in steady noise minus SRT in temporally modulated, spectral gap noise) was significant. These results indicate that the ability to take advantage of momentary fluctuations in the amplitude or frequency spectrum of background noise requires an intact active mechanism. The speech reception performance of two hearing-impaired listeners was modeled using a customized version of the expansion algorithm. The algorithm was customized to an individual's impairment based on psychoacoustic measures used to evaluate the integrity of the active mechanism. The maximum SRT difference in the simulated-loss listeners more closely matched the results of their hearing-impaired counterparts, compared to SRTs measured using the original algorithm. These results provide further evidence of the importance of the active mechanism to the perception of speech in modulated noise.
by Peninah S. Rosengard.
Ph.D.

The measurement of speech reception threshold (SRT) is best evaluated in an individual's first language. Currently there is a paucity of linguistically matched materials to measure the SRT of Zulu First Language Speakers (ZFLS) in Kwa Zulu-Natal (KZN). Therefore, the present study focused on developing and assessing a Zulu SRT word list for Zulu First language Speakers (ZFLS) in KZN, according to adapted criteria for SRT in Zulu. In addition, the application of the developed list was evaluated. The study therefore followed a two phase methodological framework. Phase one focused on the development and assessment of the word list. Phase two focused on the application of the word list in a normal hearing population from KZN. Phase one of the study was realized within a descriptive survey design and Phase two was realized using a within- participant quasi experimental design. Phase one included aims one and two of the study. Phase two included aim three of the study. However, each aim had several objectives which were realized consecutively. For aim one of the study, three objectives were achieved i.e. for objective one, 131 common bisyllabic words were identified by two Zulu speaking language interpreters and two tertiary educators. Eighty two percent of these words were described as bisyllabic verbs. The outcome of objective two concluded that 58 bisyllabic verbs were rated as being familiar, phonetically dissimilar and low tone verbs by five linguistic experts, using a three point Likert scale. The agreement among the raters was generally good for each criterion, according to the Kendall's co-efficient of concordance at 95% level of confidence. Two objectives were generated to realize aim two of the study. These included, the measurement of homogeneity of audibility of the 58 words selected in aim one and the acoustic analysis of the words. The findings for the homogeneity of audibility were based on a logistic regression analysis. Thirty normal hearing adult ZFLS (18-25 years) participated in this aim of the study. The mean slope of 50% for 28 words was 5.98%/dB. Therefore, 28 words were measured as being most homogenous. The 28 words were also assessed acoustically. The acoustic analysis indicated that the pitch contours confirm the prosodic pattern of the words selected in terms of Zulu linguistic structure, as the majority of the verbs (89%) indicated a difference in the pitch pattern between the two syllables. Furthermore, trends were noted with regard to the energy contours. The acoustical analysis supports the findings of objective one of aim two. For aim three of the study, twenty six normal hearing adult ZFLS, with functional proficiency in English were assessed. The SRT was measured using the developed Zulu SRT word list. In addition, the SRT was measured using the original CIDW2 list. The Pearson product moment correlation co-efficient was utilized for the measurement of the relationship between the SRT (Zulu) and the Pure Tone Average (PTA). Similarly, the Pearson product moment correlation between the SRT (English) and PTA was obtained. A good relationship between the SRT scores and PTA was reported when both lists were used. However, a stronger correlation between the Zulu SRT and PTA (r=.76) than with the English SRT and PTA (r=0.62) were noted. The results in aim one and aim two of the study highlighted the importance of adapting the criteria for SRT to suit the structure of the language. Aim three confirmed this premise as the implication of a stronger correlation may be related to the familiarity of the stimuli to the Zulu First Language Speaker. The study therefore contributed to both research and clinical implications. Some of the important research implications for the study include: the application of the Zulu SRT word list to a varied clinical population with a hearing disorder or loss, the standardization of the developed Zulu SRT word list on a larger sample, the development of SRT materials in other African languages in South Africa. Important clinical implications of the study include that the findings in the study support the need for speech material to be appropriate to the language of the client and the developed SRT word list in Zulu is applicable to adult ZFLS in KZN.
Thesis (M. Audiology)-University of KwaZulu-Natal, 2006.