Browsing by Author "Gilbert, Jaimie L."

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    Development, Reliability and Validity of PRESTO: A New High-Variability Sentence Recognition Test
    (American Academy of Audiology, 2013) Gilbert, Jaimie L.; Tamati, Terrin N.; Pisoni, David B.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Background: There is a pressing need for new clinically feasible speech recognition tests that are theoretically motivated, sensitive to individual differences, and access the core perceptual and neurocognitive processes used in speech perception. PRESTO (Perceptually Robust English Sentence Test Open-set) is a new high-variability sentence test designed to reflect current theories of exemplar-based learning, attention, and perception, including lexical organization and automatic encoding of indexical attributes. Using sentences selected from the TIMIT (Texas Instruments/Massachusetts Institute of Technology) speech corpus, PRESTO was developed to include talker and dialect variability. The test consists of lists balanced for talker gender, keywords, frequency, and familiarity. Purpose: To investigate the performance, reliability, and validity of PRESTO. Research design: In Phase I, PRESTO sentences were presented in multitalker babble at four signal-to-noise ratios (SNRs) to obtain a distribution of performance. In Phase II, participants returned and were tested on new PRESTO sentences and on HINT (Hearing In Noise Test) sentences presented in multitalker babble. Study sample: Young, normal-hearing adults (N = 121) were recruited from the Indiana University community for Phase I. Participants who scored within the upper and lower quartiles of performance in Phase I were asked to return for Phase II (N = 40). Data collection and analysis: In both Phase I and Phase II, participants listened to sentences presented diotically through headphones while seated in enclosed carrels at the Speech Research Laboratory at Indiana University. They were instructed to type in the sentence that they heard using keyboards interfaced to a computer. Scoring for keywords was completed offline following data collection. Phase I data were analyzed by determining the distribution of performance on PRESTO at each SNR and at the average performance across all SNRs. PRESTO reliability was analyzed by a correlational analysis of participant performance at test (Phase I) and retest (Phase II). PRESTO validity was analyzed by a correlational analysis of participant performance on PRESTO and HINT sentences tested in Phase II, and by an analysis of variance of within-subject factors of sentence test and SNR, and a between-subjects factor of group, based on level of Phase I performance. Results: A wide range of performance on PRESTO was observed; averaged across all SNRs, keyword accuracy ranged from 40.26 to 76.18% correct. PRESTO accuracy at retest (Phase II) was highly correlated with Phase I accuracy (r = 0.92, p < 0.001). PRESTO scores were also correlated with scores on HINT sentences (r = 0.52, p < 0.001). Phase II results showed an interaction between sentence test type and SNR [F(3, 114) = 121.36, p < 0.001], with better performance on HINT sentences at more favorable SNRs and better performance on PRESTO sentences at poorer SNRs. Conclusions: PRESTO demonstrated excellent test/retest reliability. Although a moderate correlation was observed between PRESTO and HINT sentences, a different pattern of results occurred with the two types of sentences depending on the level of the competition, suggesting the use of different processing strategies. Findings from this study demonstrate the importance of high-variability materials for assessing and understanding individual differences in speech perception.
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    Influence of early linguistic experience on regional dialect categorization by an adult cochlear implant user: a case study
    (Ovid Technologies (Wolters Kluwer) - Lippincott Williams & Wilkins, 2014-05) Tamati, Terrin N.; Gilbert, Jaimie L.; Pisoni, David B.; Department of Otolaryngology--Head & Neck Surgery, IU School of Medicine
    To investigate the ability of a cochlear implant user to categorize talkers by region of origin and examine the influence of prior linguistic experience on the perception of regional dialect variation. A postlingually deafened adult cochlear implant user from the Southern region of the United States completed a six-alternative forced-choice dialect categorization task. The cochlear implant user was most accurate at categorizing unfamiliar talkers from his own region and another familiar dialect region, and least accurate at categorizing talkers from less familiar regions. Although the dialect-specific information made available by a cochlear implant may be degraded compared with information available to normal-hearing listeners, this experienced cochlear implant user was able to reliably categorize unfamiliar talkers by region of origin. The participant made use of dialect-specific acoustic-phonetic information in the speech signal and previously stored knowledge of regional dialect differences from early exposure before implantation despite an early hearing loss.
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    List Equivalency of PRESTO for the Evaluation of Speech Recognition
    (American Academy of Audiology, 2015-06) Faulkner, Kathleen F.; Tamati, Terrin N.; Gilbert, Jaimie L.; Pisoni, David B.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    BACKGROUND: There is a pressing clinical need for the development of ecologically valid and robust assessment measures of speech recognition. Perceptually Robust English Sentence Test Open-set (PRESTO) is a new high-variability sentence recognition test that is sensitive to individual differences and was designed for use with several different clinical populations. PRESTO differs from other sentence recognition tests because the target sentences differ in talker, gender, and regional dialect. Increasing interest in using PRESTO as a clinical test of spoken word recognition dictates the need to establish equivalence across test lists. PURPOSE: The purpose of this study was to establish list equivalency of PRESTO for clinical use. RESEARCH DESIGN: PRESTO sentence lists were presented to three groups of normal-hearing listeners in noise (multitalker babble [MTB] at 0 dB signal-to-noise ratio) or under eight-channel cochlear implant simulation (CI-Sim). STUDY SAMPLE: Ninety-one young native speakers of English who were undergraduate students from the Indiana University community participated in this study. DATA COLLECTION AND ANALYSIS: Participants completed a sentence recognition task using different PRESTO sentence lists. They listened to sentences presented over headphones and typed in the words they heard on a computer. Keyword scoring was completed offline. Equivalency for sentence lists was determined based on the list intelligibility (mean keyword accuracy for each list compared with all other lists) and listener consistency (the relation between mean keyword accuracy on each list for each listener). RESULTS: Based on measures of list equivalency and listener consistency, ten PRESTO lists were found to be equivalent in the MTB condition, nine lists were equivalent in the CI-Sim condition, and six PRESTO lists were equivalent in both conditions. CONCLUSIONS: PRESTO is a valuable addition to the clinical toolbox for assessing sentence recognition across different populations. Because the test condition influenced the overall intelligibility of lists, researchers and clinicians should take the presentation conditions into consideration when selecting the best PRESTO lists for their research or clinical protocols.
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    Some Factors Underlying Individual Differences in Speech Recognition on PRESTO: A First Report
    (American Academy of Audiology, 2013) Tamati, Terrin N.; Gilbert, Jaimie L.; Pisoni, David B.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Background: Previous studies investigating speech recognition in adverse listening conditions have found extensive variability among individual listeners. However, little is currently known about the core underlying factors that influence speech recognition abilities. Purpose: To investigate sensory, perceptual, and neurocognitive differences between good and poor listeners on the Perceptually Robust English Sentence Test Open-set (PRESTO), a new high-variability sentence recognition test under adverse listening conditions. Research design: Participants who fell in the upper quartile (HiPRESTO listeners) or lower quartile (LoPRESTO listeners) on key word recognition on sentences from PRESTO in multitalker babble completed a battery of behavioral tasks and self-report questionnaires designed to investigate real-world hearing difficulties, indexical processing skills, and neurocognitive abilities. Study sample: Young, normal-hearing adults (N = 40) from the Indiana University community participated in the current study. Data collection and analysis: Participants' assessment of their own real-world hearing difficulties was measured with a self-report questionnaire on situational hearing and hearing health history. Indexical processing skills were assessed using a talker discrimination task, a gender discrimination task, and a forced-choice regional dialect categorization task. Neurocognitive abilities were measured with the Auditory Digit Span Forward (verbal short-term memory) and Digit Span Backward (verbal working memory) tests, the Stroop Color and Word Test (attention/inhibition), the WordFam word familiarity test (vocabulary size), the Behavioral Rating Inventory of Executive Function-Adult Version (BRIEF-A) self-report questionnaire on executive function, and two performance subtests of the Wechsler Abbreviated Scale of Intelligence (WASI) Performance Intelligence Quotient (IQ; nonverbal intelligence). Scores on self-report questionnaires and behavioral tasks were tallied and analyzed by listener group (HiPRESTO and LoPRESTO). Results: The extreme groups did not differ overall on self-reported hearing difficulties in real-world listening environments. However, an item-by-item analysis of questions revealed that LoPRESTO listeners reported significantly greater difficulty understanding speakers in a public place. HiPRESTO listeners were significantly more accurate than LoPRESTO listeners at gender discrimination and regional dialect categorization, but they did not differ on talker discrimination accuracy or response time, or gender discrimination response time. HiPRESTO listeners also had longer forward and backward digit spans, higher word familiarity ratings on the WordFam test, and lower (better) scores for three individual items on the BRIEF-A questionnaire related to cognitive load. The two groups did not differ on the Stroop Color and Word Test or either of the WASI performance IQ subtests. Conclusions: HiPRESTO listeners and LoPRESTO listeners differed in indexical processing abilities, short-term and working memory capacity, vocabulary size, and some domains of executive functioning. These findings suggest that individual differences in the ability to encode and maintain highly detailed episodic information in speech may underlie the variability observed in speech recognition performance in adverse listening conditions using high-variability PRESTO sentences in multitalker babble.