Source: Dissertation Abstracts International, Volume: 31-05, Section: B, page: 2780. / Thesis (Ph.D.)--The Florida State University, 1970.

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No description available.

No description available.

Thesis (Ph.D.)--Indiana University, Dept. of Speech and Hearing, 2009. / Title from PDF t.p. (viewed on Feb. 10, 2010). Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3401. Adviser: Larry E. Humes.

<p> The Occupational Safety and Health Administration estimates that each year, approximately 30 million people are occupationally exposed to hazardous noise. While many are aware of the noise exposure associated with industrial occupations, there has been little research conducted on bartenders who often work in environments that have high levels of noise. The majority of current published research on occupational noise exposure of bartenders has only evaluated noise levels on one night of business. Bartenders often work multiple days per week, which vary in the amount of patrons and entertainment provided, this variation in business leads to variation in the amount of noise to which they are exposed. </p><p> The purpose of this research study was to gather occupational noise exposure data for bartenders during a workweek at a Tampa Bay bar establishment that hosts live music on weekends. Personal noise dosimeters were used to collect personal noise exposure data. Area noise level data were collected using a sound level meter. While several bar establishments were approached, one bar establishment part pated as the study site and noise data were collected for seven consecutive days (Thursday-Wednesday). Personal noise exposure data were collected for an entire 8-hour work shift for the Thursday-Sunday portion of the study, and for 6 hours for the Monday-Wednesday portion of the study. Area noise data were collected for the Thursday-Saturday portion of the study. </p><p> Results of this study indicate that the highest noise exposure for either bartender occurred on Saturday (Bartender 1: 93.1 dBA; Bartender 2: 83.6 dBA) when a live band was performing in the establishment. Using the OSHA Hearing Conversation and OSHA PEL measurement methods, Bartender 1 was exposed to excessive noise levels (>85 dBA) on four (4) nights of the study, while Bartender 2 had no exposures over 85 dBA. However, using the ACGIH measurement method, Bartender 1 was exposed to excessive noise levels six (6) nights of the study, while Bartender 2 was exposed to excessive noise levels two (2) nights of the study.</p>

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

No description available.

Introduction: Current newborn hearing screening include testing with otoacoustic emission and automated auditory brainstem response. Unfortunately, both tests are affected by the presence of material in the ear canal and middle ear such as vernix, meconium and amniotic fluid. The primary objective of this study was to perform wideband measurements and otoscopy on newborns in order to determine whether occlusion of the ear canal affects the wideband measurements. A secondary objective was to compare the wideband measurements obtained after birth to those taken at 14 to 28 days later. A third objective was to obtain additional wideband normative data in newborns. Materials and Methods: Newborns from a well-baby nursery were enrolled. Wideband measurements under both ambient and pressurized conditions and otoscopy were done immediately after the hearing screening and between 14 and 28 days later. Occlusion of the ear canal as seen on otoscopy was described on a scale of 0 to 100% in increments of 10.Results: A total of 156 babies were enrolled. On the first measurement, a statistically significant difference in reflectance was found between 0-70% and 80-100% occlusion groups and between 6 groups of frequencies between 250 Hz and 8 kHz. There was no significant difference in reflectance between the right and the left ears. A comparison of reflectance under pressurised conditions between the first and second measurements has shown a higher reflectance at the negative pressure region during the first few days of life. Conclusion: Significant increase in reflectance occurs when 70% to 80% of the ear-canal diameter is occluded. A trend of higher reflectance appears to be present when the canal is pressurized to negative values. A comparison of reflectance between the present study and previous studies is given. / Introduction: Le dépistage néonatal de la surdité actuel inclut l'évaluation d'émissions oto-acoustiques automatisées et la réponse évoquée auditive du tronc cérébral. Malheureusement, les résultats de ces tests peuvent être affectés par la présence de matériaux transitoires dans le conduit auditif externe et l'oreille moyenne comme par exemple le vernix, le méconium et le liquide amniotique. L'objectif primaire de cette étude était d'effectuer des mesures de réflectance à large bande et un examen otoscopique sur les nouveau-nés afin de déterminer si l'occlusion du conduit auditif externe affecte les mesures à large bande. Un objectif secondaire était de comparer les mesures après la naissance à celles obtenues 14 à 28 jours plus tard. Le troisième objectif était d'obtenir des données normatives supplémentaires. Matériels et méthodes: De nouveau-nés d'une pouponnière de bébés en santé ont été inscrits. Les mesures à large bande, effectuées dans des conditions ambiantes et sous pression, et l'examen otoscopique ont été exécutés immédiatement après le dépistage de la surdité et entre 14 et 28 jours plus tard. L'occlusion du conduit auditif externe, vu par examen otoscopique, a été décrite par une échelle de 0 à 100% d'obstruction, par étapes de 10%. Résultats: Un total de 156 bébés ont été inscrits. Lors de la première mesure, une différence statistiquement significative a été observée entre les groupes 0-70% et 80-100% d'obstruction du conduit, et également entre les 6 groupes de fréquences auditives comprises entre 250 Hz et 8 kHz. Il n'y avait aucune différence significative entre l'oreille droite et la gauche. Une comparaison des résultats dans des conditions sous pression, entre la première et la deuxième mesure, a démontré un coefficient de réflectance supérieur à la zone de pression négative pendant les premiers jours de vie.Conclusion: Une augmentation significative de la réflectance se produit lorsque le conduit auditif externe est obstrué de 70% à 80%. Une tendance de réflectance plus élevée semble être présente lorsque le canal est sous pression, à des valeurs négatives. Une comparaison des résultats de cette étude et d'études antérieures est discutée.

The diagnostic utility of tympanometry with respect to distinguishing healthy and otosclerotic ears was investigated in four studies. This issue was examined with respect to alternative measures of static immittance (SI), tympanometric shape, resonant frequency (RF), and frequency corresponding to admittance phase angle of 45 degree (F45°) obtained from 68 healthy ears and 36 ears with surgically confirmed otosclerosis. Study 1 served to replicate previous findings that otosclerotic and healthy ears differ with respect to F45° and RF but not SI and TW measured at 226 Hz, thus confirming the advantage of multifrequency measures over standard low frequency tympanometric measures in differentiating healthy and otosclerotic ears. Studies 2 and 3 examined the effect of probe tone frequency on the diagnostic utility of SI and tympanometric shape. Group differences were evident for SI measured using a probe tone near the frequency corresponding to F45°, in the present study the optimal probe frequency was 630 Hz. Group differences were not evident for tympanometric width (TW) at 226 Hz, 350, and 450 Hz whereas the two groups differed in distribution of Vanhuyse patterns of 1B1G and 3B1G observed at frequencies between 800 Hz and 1250 Hz. In study 4 the diagnostic performance of five different tympanometric parameters was assessed using test performance and receiver operating characteristic (ROC) analysis. Results showed that F45° was the best single measure to distinguish healthy ears from otosclerotic ears; RF and SI measured at 630 Hz were the next best measures followed by Vanhuyse patterns; TW was the least useful measure. However, when compared using optimal decision criterion (derived from ROC analysis) differences in test performance for F45° and SI measured at 630 Hz were small suggesting that their clinical utility is comparable. Correlations and patterns of individual performance also confirm the presence of two independent signs of otoscle