Abstract The symptom complex originating from the inner ear, known as Meniere's disease, was studied especially from the epidemiologic point of view. A total of 442 patients' charts were retrospectively analysed in several hospital districts of Finland. The period of 1992-1996 was covered. The main focus was on the epidemiological assessment of the disease in Finland. To clarify the epidemiological figures, the validity of the diagnostic assessment was examined using the latest guidelines (1995) of the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS) as a gold standard. The diagnostic tools used in the different hospitals were documented and evaluated, and diagnostic accuracy at the different levels of the health care system was evaluated. The clinical picture of Meniere's disease was characterised, and the therapeutic modalities used were evaluated. The audiometric configurations were classified according to two principles. The prognosis of hearing impairment was specified by creating a multivariable model. Half of the patients (N = 221) fulfilled the AAO-HNS criteria for definite disease. The prevalence and incidence of definite cases of Meniere's disease appeared to be lower in Finland than could be expected based on previous international studies. A prevalence of at least 43 per 100,000 and an average annual incidence of 4.3 per 100,000 were obtained. The prevalence rates in the catchment areas of the university and central hospitals did not differ statistically, but a significant (p < 0.001) difference was found between the average prevalences in the northern and southern Finnish hospital districts. Fluctuation of hearing in repeated audiometric measurements appeared to be a highly sensitive (94%) diagnostic test to detect definite Meniere's disease. According to the multivariable model created in this study, the hearing impairment in Meniere's disease affects equally males and females, and the deterioration is about 1 dB per year due to the duration of the disease and 0.5 dB per year due to aging. The disease was controlled conservatively in 69% of the cases. A gently sloping high-frequency audiometric pattern was most prevalent according to the EU Work Group classification and a flat pattern according to the mid-frequency-based classification. The variability of diagnostic criteria, diagnostic tools and therapeutic modalities shows an evident need for up-to-date therapy recommendations for Meniere's disease in Finland.

The limited amount of normative information regarding speech motor development in the clinically important age range four to seven years served as motivation for this study. The main aim of the study was to collect normative information regarding sensorimotor speech control skills of pre-school children. The method of the study was designed and the results interpreted within the framework of the four-level model of speech production of Van der Merwe (1997). Basic qualitative and quantitative data were gathered for a variety of aspects of speech motor development in Afrikaans-speaking children aged 4;0 to 6;7 years in the following areas: 1) non-speech oral movements, 2) non-speech diadochokinesis, 3) speech diadochokinesis, 4) cluster production, 5) word syllable structure in spontaneous speech, 6) acoustic data regarding first-vowel duration and variability of first-vowel duration in repeated utterances of the same word, 7) acoustic voice onset time data, 8) acoustic data regarding first-syllable duration in words of increasing length. Results indicated that associated movements and accuracy errors occurred in some non-speech oral movement and non-speech diadochokinesis tasks. Normative, diadochokinetic rate data were gathered. Perceptual analysis indicated difficulty with glottal and three-place diadochokinesis tasks. Subjects produced 84% of initial clusters in isolation correctly and 79% of final clusters. Schwa-vowel insertions occurred in clusters in isolation, but not in spontaneously produced words. Subjects produced 163 different word syllable structures in spontaneous speech, with 18 structures occurring in all subjects’ data. Six-year-olds generally displayed the shortest first-vowel duration. Individual, non-age related trends occurred for variability of first-vowel duration. Mean voice onset times in voiced stop contexts ranged from -97ms to +12ms, with overall instances of mean voicing lead occurring in 27% of the four-year olds’ productions, 4% of the five-year-olds’ productions and 80% of the six-year-olds’ productions. Mean voice onset times in voiceless stop contexts ranged from +11ms to +37ms. Subjects adapted first-syllable duration to word length by decreasing it as the word length increased. Results indicated that a wide range of normal speech motor performance is possible for children this age, and that individuals can display different performance levels for different speech parameters. This emphasizes the complexity of speech motor development and the need to assess a variety of speech motor parameters. It is essential that quantitative (objective) analysis of children’s speech motor performance be supplemented with qualitative (descriptive) analysis. The study contributed knowledge to the understanding of certain aspects of speech motor development and to the speech production process in general. / Dissertation (MComm Path)--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / Unrestricted

In the evaluation of special populations, such as neonates, infants and malingerers, audiologists have to rely heavily on objective measurements to assess hearing ability. Current objective audiological procedures such as tympanometry, the acoustic reflex, auditory brainstem response and transient evoked otoacoustic emissions, however, have certain limitations, contributing to the need of an objective, non-invasive, rapid, economic test of hearing that evaluate hearing ability in a wide range of frequencies. The purpose of this study was to investigate distortion product otoacoustic emissions (DPOAEs) as an objective test of hearing. The main aim was to improve prediction of pure tone thresholds at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz with DPOAEs and artificial neural networks (ANNs) in normal and hearing-impaired ears. Other studies that attempted to predict hearing ability with DPOAEs and conventional statistical methods were only able to distinguish between normal and impaired hearing. Back propagation neural networks were trained with the pattern of all present and absent DPOAE responses of 11 DPOAE frequencies of eight DP Grams and pure tone thresholds at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz. The neural network used the learned correlation between these two data sets to predict hearing ability at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz. Hearing ability was not predicted as a decibel value, but into one of several categories spanning 1 OdB. Results for prediction accuracy of normal hearing improved from 92% to 94% at 500 Hz, 87% to 88% at 1000 Hz, 84% to 88% at 2000 Hz and 91% to 93% at 4000 Hz from the De Waal (1998) study to the present study. The improvement of prediction of normal hearing can be attributed to extensive experimentation with neural network topology and manipulation of input data to present information to the network optimally. The prediction of hearing-impaired categories was less satisfactory, due to insufficient data for the ANNs to train on. A prediction versus ear count correlation strongly suggested that the inaccurate predictions of hearing-impaired categories is not a result of an inability of DPOAEs to predict pure tone thresholds in hearing impaired ears, but a result of insufficient data for the neural network to train on. This research concluded that DPOAEs and ANNs can be used to accurately predict hearing ability within 10dB in normal and hearing-impaired ears from 500 Hz to 4000 Hz for hearing losses of up to 65dB HL. / Thesis (DPhil (Communication Pathology))--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / unrestricted

O trabalho teve como objetivo geral discutir a construção de listas de palavras para uso na medida do teste de Limiar de Reconhecimento da Fala (LRF) em crianças com idade entre 5 e 7 anos. O grupo de sujeitos foi constituído por alunos de pré-escola e da 1ª série do ensino fundamental de escolas da rede pública da cidade de Itatiba, São Paulo, otologicamente normais. O trabalho foi estruturado em 3 etapas. A primeira etapa relacionou-se com a construção das listas de palavras experimentais trissilábicas paroxítonas denominadas de LE1 e 2, constituídas a partir de um levantamento feito com programas e filmes infantis de maior audiência pelos grupos etários estudados. Das 672 palavras obtidas, 35 trissílabas paroxítonas foram selecionadas, formando duas listas em ordem aleatória. As listas LRS 1 e 2 foram utilizadas para comparação e retiradas de Russo e Santos (1993), seguindo os mesmos critérios de elaboração. Na segunda etapa, as listas de palavras foram gravadas em estúdio profissional, por um locutor do sexo feminino nativo do português brasileiro. Na terceira etapa o material desenvolvido foi aplicado em um grupo de 94 crianças de 5 a 7 anos de ambos os sexos. Os resultados, na análise quantitativa, não mostraram diferenças estatisticamente significantes entre as variáveis listas, orelhas, faixa etária, ordem de apresentação e sexo. Os resultados do LRF (em deciBel Nível de Sensação) obtidos com as listas LE e LRS situaram-se entre -10 e +15dBNS com média de 4,3dBNS para orelha direita e 4,4dBNS para orelha esquerda. Os dados indicaram que as listas desenvolvidas para a obtenção do LRF, em crianças na faixa etária do estudo, são válidas para este fim. A análise qualitativa indicou algumas das estratégias utilizadas pelos sujeitos no reconhecimento auditivo das palavras da lista E1. / This study provides a discussion about a word list construction to use in the speech recognition threshold. The chosen subjects are pre and first year school children from the Basic Education at public schools in Itatiba, São Paulo – Brazil, otologically normal. The study comprises three stages. The first one was the construction of paroxytone trisyllabic word lists called LE1 e 2, consisted of a survey done with juvenile programs and films of bigger audience by the aged studied groups. From the 672 words, 35 paroxytone trisyllables were selected, forming two lists in a random order. The LRS 1 and 2 were used for comparison and they were got from Russo e Santos (1993), following the same criteria. In the second stage, the word lists were recorded in a professional studio by a native speaker. In the third stage, the developed material was applied in a group with 94 children. The results didn’t show differences statistically significant among the varied list, the ear, the aged group, the presentation order and the sex. The SRT (dBNS) results obtained with the LE and the LRS lists were placed among -10 and +15 dBNS. The data indicated that the developed lists to obtain the SRT in these children are valid.

Current methods of selection of amplification are not readily applicable to children, and relatively few alternatives have been explored. Consequently, the audiologist must make a number of rather arbitrary judgements with little concrete information to support his recommendation of a given instrument. He has limited means of clinically determining the sustainability of the instrument for the child. This study was designed to explore the relationship between several factors which may add to the existing body of data related to the problems of amplification in children. In brief, the problem was to determine the various electrical and acoustical characteristics of hearing aids worn by children under study. A comparison of this information with hearing loss data would be studied to aid in understanding what relationships (if any) exist between the two measures. If in fact there is a relationship between the factors of hearing loss and hearing aid characteristics, this information may provide a more comprehensive and precise means of examining a given hearing aid in view of the hearing loss specific to each child. While this information may be preliminary in nature, it has application in the development of ongoing programs of evaluation and maintenance of hearing aids. A brief comparison of the present performance of the instrument with both the original performance levels and the child’s current needs would appear to be an integral part of such a program.

The first part of the thesis focuses on theory and deals with the basic physical terms as far as acoustics is concerned. It also deals with a description of auditory system, as well as graphical results of audiometrical methods. The second part to the thesis deals with a scheme of audiometer for hearing tests. It also deals with the description of the programme as well as the transfer of the decibel scale to electric voltage and its correction. The last chapter contains the data collected during the hearing tests.

Decentralised detection and monitoring of hearing loss can be supported by new mHealth technologies using automated testing, which can be facilitated by minimally trained persons. These technologies may prove particularly useful in an infectious disease (ID) clinic setting where patients are at high risk for hearing loss. The current study aimed to evaluate the clinical utility of mobile and automated audiometry hearing health technology in an ID clinic setting. The current study was exploratory as it aimed to determine whether smartphone automated audiometry and South African English Digits-In-Noise (SA Eng DIN) smartphone applications could be utilised in an infectious disease clinic setting to monitor an HIV-related hearing loss in a feasible and time efficient way. Smartphone automated audiometry (hearTest™) and speech-in-noise testing (SA English Digits-In-Noise (DIN) test) were compared with manual audiometry at 2, 4, and 8 kHz. Smartphone automated audiometry and the DIN test were repeated to determine the test re-test reliability. Two hundred subjects (73% female and 27% male) were enrolled. Fifty participants were re-tested with the smartphone applications. Participants’ ages ranged from 18 to 55 years with a mean age of 44.4 (8.7 SD). Threshold comparisons were made between smartphone audiometry testing and manual audiometry. Smartphone automated audiometry, manual audiometry, and test re-test measures were compared to determine the statistical significance of any differences observed using the Wilcoxon signed-ranked test. Spearman rank correlation test was used to determine the relationship between the smartphone applications and manual audiometry, as well as for test re-test measurements. For all participants, 88.2% of thresholds corresponded within 10 dB or less between smartphone audiometry and manual audiometry. There was a significant difference (p>0.05) between smartphone and manual audiometry for the right ear at 4 and 8 kHz and the left ear at 2 and 4 kHz respectively. No significant difference was noted (p>0.05) between test and re-test measures of smartphone technology except at 4kHz in the right ear in smartphone automated audiometry. The absolute average difference between the initial and re-test of DIN testing was 1.2 dB (1.5 SD). No significant difference was noted in the test re-test measures of the DIN test (p < vii 0.05). A correlation coefficient of 0.56 was present in the DIN test re-test measures when the Spearman rank correlation test was administered. Smartphone audiometry with calibrated headphones provides reliable results and can be used as a baseline and monitoring tool at ID clinics. / Dissertation (MA)--University of Pretoria, 2017. / Speech-Language Pathology and Audiology / MA / Unrestricted

Aim of the study: To evaluate the influence of high frequency hearing loss (>8000 Hz) on distortion product otoacoustic emissions registered in the frequency range from 0,5 to 8 kHz. Material and methods: 280 ears with tinnitus and normal hearing (0.25–8 kHz) divided into 3 groups depending on the degree of high frequency hearing loss: group A – hearing threshold up to 20 dB for 10, 12.5, 14 and 16 kHz (68 ears); group B – hearing threshold 25–40 dB HLfor at least one of four EHfs (93 ears); group C – hearing threshold above 40 dB HL for at least one of four EHFs (119 ears). For each group mean audiogram and DP-gram were obtained and statistical analysis was used for comparison across these groups. Results: Mean DPOAE values in group C were significantly lower in comparison with group A for the frequency range 2–8 kHz, and in comparison with group B were significantly lower for the frequency range 4–8 kHz. Conclusions: High frequency hearing loss (above 8 kHz) has a relevant influence on distortion product otoacoustic emissions registered at frequencies below 8 kHz in tinnitus patients. The greater is hearing loss above 8 kHz, the lower is DPOAE value below 8 kHz.

A computer-based audiometric evaluation system has been developed. The system makes use of an IBM PC/XT/AT compatible personal computer to perform pure tone and speech tests and · comprises a plug-in card and custom software. The card contains pure tone and masking noise generators, together with amplifiers for a. set of headphones .and bone conduction transducer, patient and audiologist microphone amplifiers and a hand-held infra-red remote-control unit. A voice-operated gain-adjusting device on the audiologist's microphone eliminates the need for a sound pressure level meter during speech tests. The software-based user-interface makes use.of overlaid pop-up menus, context sensitive assistance.and a text editor on a graphics screen. Pure tone and speech data are acquired and displayed on a dynamic audiogram and speech discrimination gram respectively. This data may be stored and later retrieved from a patient data base. Further audiometric tests may be incorporated at a later stage.

The purpose of this study was to investigate the effects of a 500 Hz and 3150 Hz one-third octave band augmentation on the speech discrimination ability of normal hearing listeners and whether such effects vary with signal presentation level. The augmented portion of monosyllabic words was systematically varied from 5-55dB above the intensity level of the unfiltered version of the words and presented simultaneously to one ear.