The purpose of this thesis was to investigate the California Consonant Test by manipulating selected variables to determine whether it would be a reliable and valid alternative to the presently used CID W-22 word lists with the sensorineural hearing loss population. This study also looked at the scores obtained on the two discrimination tests and the scores obtained on the Profile Questionnaire for Rating Communicative Performance. In this way, a closer look was taken to determine how much difficulty hearing impaired individuals were reportedly experiencing in understanding speech as compared to their actual performance on the two discrimination tests.The test population consisted of 16 male and 16 female subjects with bilateral symmetrical, sensorineural hearing losses. The CID W-22 Auditory Test and the California Consonant Test (live voice and recorded presentations) were administered to each subject under aided and unaided conditions. At the end of each testing session, each subject was asked to answer the Profile Questionnaire for Rating Communicative Performance in a Home Environment.Pearson's Product-Moment Correlation Coefficient and t-tests for independent measures were calculated to determine if significant correlations existed.It was concluded from this investigation that the California Consonant Test is a more sensitive indicator of the phoneme difficulties experienced by the individuals with &high frequency sensorineural hearing loss than is the' CID W-22 Auditory Test. Although significant correlations were not obtained between the two discrimination tests and the questionnaire, a question by question analysis indicated that all the individuals had at least some difficulties in all situations proposed in this questionnaire. It would therefore seem that the California Consonant Test is a more accurate indicator of the individual's problems in the communicative situation.

This study investigates the performance of two hemispherec-tomized subjects and ten normal subjects on a dichotic binaural frequency fusion (DBFF) test and on a competing dichotic message test. The DBFF test was designed to examine whether binaural integration of two complementary frequency segments of the same word, dichotically presented, necessitates the presence of two intact hemispheres. The competing dichotic message test was presented to provide a measure of the extent of strengthening of ipsilateral pathways in the hemispherectomized subjects. The DBFF test consisted of three fifty-word CNC lists which were processed through two band-pass filters and recorded on a two--channel magnetic tape. The test consisted of two binaural conditions. In the Dichotic A condition, the high band was delivered to the left ear and the low band to the right. The Dichotic B condition was the reverse of the first. For each condition 50 phonetically balanced (PB) words were presented and the subject was required to repeat the word in a 4 second interval between words. The competing dichotic message test consisted of 15 sets of three pairs of words, one of each pair being presented simultaneously to either ear, using stereophonic head-phones. The subject was required to repeat as many words from each set as possible. The Z scores, measuring the deviation in standard deviation units of the raw scores of the operated subjects from the mean scores of the normals indicated that the removal of a hemisphere did not significantly decrease the scores of two hemispherectomized subjects on a DBFF test. Removal of a hemisphere, however, decreased the scores of the hemispherectomees on the competing dichotic message test in one of the ears -- specifically the ear contralateral to the removed hemisphere. A comparative analysis of how the central auditory nervous system (CANS) of a hemispherectomized subject might process a complementary dichotic message (exemplified by the DBFF test), as opposed to a competing dichotic message, provides an interesting basis for a discussion on the nature of the "biological detector" of speech elements in the CANS. / Medicine, Faculty of / Audiology and Speech Sciences, School of / Graduate

The purpose of the study was to evaluate the sensitivity of the CID Everyday sentences, with competing cafeteria noise, as a measure of the real life receptive communication difficulty experienced by subjects with hearing loss limited to frequencies above 2000 Hz. In order to establish normative data the speech discrimination test w~s given to 38 normal hearing subjects (aged 19-46). Second, the discrimination test was given to 12 hearing impaired subjects (29-64), who also completed a self-assessment questionnaire, the Hearing Handicap Inventory for Adults (HHIA). The results were analyzed to determine: (a) if there was a significant difference between the mean scores of the normal hearing and the hearing impaired subjects, and (b) if there was a significant correlation between the hearing impaired subjects' scores on the discrimination test and those obtained on the HHIA. The investigation revealed that a statistically significant difference (p=0.04) existed between the mean scores of the two subject groups on the discrimination test. The hearing impaired subjects averaged about 9% below the normal hearing subjects. Although there was a weak to moderate correlation between the hearing impaired subjects' scores on the discrimination test and their scores on the HHIA, it was not statistically significant. It was concluded that, with further research, the CID Everyday sentences, with competing cafeteria noise, have potential merit as a speech discrimination procedure to quantify the hearing handicap produced by a high frequency hearing loss.

Tinnitus is a conscious perception of phantom sounds in the absence of external acoustic stimuli, and masking is one of the popular ways to treat it. Due to the variation in the perceived tinnitus sound from patient to patient, the usefulness of masking therapy cannot be generalized. Thus, it is important to first determine the feasibility of masking therapy on a particular patient, by quantifying the tinnitus sound, and then generate an appropriate masking signal. This paper aims to achieve this kind of individual profiling by developing interactive software -Tinnitus Analyzer, based on clinical approach. The developed software has been proposed to be used in place of traditional clinical methods and this software (as a part of the future work) will be implemented in the practical scenario involving real tinnitus patients. / by Bashali Chaudbury. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Professional research project (Au.D.)--University of South Florida, 2000. / Title from PDF of title page. / Document formatted into pages; contains 48 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The primary objective of the project was to survey recognized "experts" in the field of neurodiagnostic audiology and practicing audiologists regarding their referral criteria and referral patterns for administering an auditory brainstem response test (ABR). For purposes of this study, "expert" was defined as any recognized audiologist with at least two or more publications and/or seminarsin the field of auditory evoked potentials. / Responses of experts and practicing audiologists were compared and contrasted to establish: a) if there was a standard referral pattern; b) what, if any, were the apparent critical components of referral patterns; and, c) whether or not current practice reflected the utilization of such critical components. The survey was designed to establish whether the respondent was practicing, in what type of practice setting, and how often ABRs were performed. Specificity and sensitivity of ABR outcomes was also requested. / The survey was administered verbally, via telephone, to 3 experts and was sent via e-mail to 178 randomly selected audiologists in the United States. Of the latter 53 returned, 38 reported conducting ABRs. Thus, data analysis was reported on 38 respondents. The survey results did not reveal a consistent standard referral pattern. Critical components for referral were hypothesized based on the "expert" majority response. These include ABR referral based on the presence of: (1) asymmetric sensorineural hearing loss; (2) unilateral tinnitus; (3) positive reflex decay; and, (4) word recognition rollover. The majority of "non-expert" practitioners surveyed reported that these symptoms warranted consideration for referral, thus reflecting utilization of apparent critical components. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

published_or_final_version / abstract / toc / Speech and Hearing Sciences / Master / Master of Science in Audiology

This study assessed the effective use of pure-tone testing versus speech testing as used to predict the degree of hearing handicap experienced by an individual. Twenty-one subjects over the age of 65 were tested. Each subject was administered the following test battery: spondee threshold; a pure-tone evaluation, including air and bone conduction; Speech Perception in Noise (SPIN) test; Synthetic Sentence Identification (SSI) test; NU-6 for speech discrimination; establishment of most comfortable listening level (MCL) and loudness discomfort listening level (LDL); immittance testing including tympanograms, acoustic reflex thresholds, and reflex decay.

published_or_final_version / Speech and Hearing Sciences / Master / Master of Science in Audiology

Lee Yuet-sheung. / "May 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 352-361). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

[Truncated abstract] The present study investigated whether any of the characteristics of the compound action potential (CAP) waveform or the spectrum of the neural noise (SNN) recorded from the cochlea, could be used to examine abnormal spike generation in the type I primary afferent neurones, possibly due to pathologies leading to abnormal hearing such as tinnitus or tone decay. It was initially hypothesised that the CAP waveform and SNN contained components produced by the local action currents generated at the peripheral ends of the type I primary afferent neurones, and that changes in these local action currents occurred due to changes in the membrane potential of these neurones. It was further hypothesised that the lateral olivo-cochlear system (LOCS) efferent neurones regulate the membrane potential of the primary afferent dendrites to maintain normal action potential generation, where instability in the membrane potential might lead to abnormal primary afferent firing, and possibly one form of tinnitus. We had hoped that the activity of the LOCS efferent neurones could be observed through secondary changes in the CAP waveform and SNN, resulting from changes in the membrane potential of the primary afferent neurones. The origins of the neural activity generating the CAP waveform and SNN peaks, and the effects of the LOCS on the CAP and SNN were experimentally investigated in guinea pigs using lesions in the auditory system, transient ischemia and asphyxia, focal and systemic temperature changes, and pharmacological manipulations of different regions along the auditory pathway. ... Therefore, the CAP and SNN are altered by changes in the propagation of the action potential along the primary afferent neurones, by changes in the morphology of the tissues surrounding the cochlear nerve, and by changes in the time course of the action currents. If the CAP waveform is not altered, the amplitude of the 1kHz speak in the spontaneous SNN can be used as an objective measure of the spontaneous firing rate of the cochlear neurones. However, because the SNN contains a complex mixture of neural activity from all cochlear neurones, and the amplitude of the spontaneous SNN is variable, it would be difficult to use the spontaneous SNN alone as a differential diagnostic test of cochlear nerve pathologies. To record extratympanic electrocochleography (ET ECochG) from humans, a custom-designed, inexpensive, low-noise, optically isolated biological amplifier was built. Furthermore, a custom-designed extratympanic active electrode and ear canal indifferent electrode were designed, which increased the signal-to-noise ratio of the ECochG recording by a factor of 2, decreasing the overall recording time by 75%. The human and guinea pig CAP waveforms recorded in the present study appeared similar, suggesting that the origins of the human and guinea pig CAP waveforms were the same, and that experimental manipulations of the guinea pig CAP waveform can be used to diagnose the cause of abnormal human ECochG waveforms in cases of cochlear nerve pathologies.