The need for hearing health care services across the world far outweighs the capacity to deliver these services with the present shortage of hearing health care personnel. Automated test procedures coupled with telemedicine may assist in extending services. Automated threshold audiometry has existed for many decades; however, there has been a lack of systematic evidence supporting its clinical use. The aim of this study was to systematically review the current body of peer-reviewed publications on the validity (test-retest reliability and accuracy) of automated threshold audiometry. A meta-analysis was thereafter conducted to combine and quantify the results of individual reports so that an overall assessment of validity based on existing evidence could be made for automated threshold audiometry. A systematic literature review and meta-analysis was conducted using peerreviewed publications. A multifaceted approach, covering several databases and employing different search strategies, was utilized to ensure comprehensive coverage and crosschecking of search findings. Publications were obtained using the following three databases: Medline, SCOPUS and PubMed, and by inspecting the reference list of relevant reports. Reports were selected based according to inclusion and an exclusion criterion, thereafter data extraction was conducted. Subsequently, the meta-analysis combined and quantified data to determine the validity of automated threshold audiometry. In total, 29 articles met the inclusion criteria. The outcomes from these studies indicated that two types of automated threshold testing procedures have been utilized, the ‘method of limits’ and ‘method of adjustments’. Reported findings suggest accurate and reliable thresholds when utilizing automated audiometry. Most of the reports included data on adult populations using air conduction testing, limited data on children, bone conduction testing and the effects of hearing status on automated threshold testing were however reported. The meta-analysis revealed that test-retest reliability for automated threshold audiometry was within typical testretest reliability for manual audiometry. Furthermore, the meta-analysis showed comparable overall average differences between manual and automated air conduction audiometry (0.4 dB, 6.1 SD) compared to test-retest differences for manual (1.3 dB, 6.1 SD) and automated (0.3 dB, 6.9 SD) air conduction audiometry. Overall, no significant differences (p>0.01; Summarized Data ANOVA) were obtained in any of the comparisons between test-retest reliability (manual and automated) and accuracy. Current evidence demonstrates that automated threshold audiometry can produce an accurate measure of hearing threshold. The differences between automated and manual audiometry fall within typical test-retest and inter-tester variability. Despite its long history however, validation is still limited for (i) automated bone conduction audiometry; (ii) automated audiometry in children and difficult-to-test populations and; (iii) automated audiometry with different types and degrees of hearing loss. / Dissertation (MCommunication Pathology)--University of Pretoria, 2013. / gm2014 / Speech-Language Pathology and Audiology / unrestricted

Made available in DSpace on 2016-04-27T18:12:12Z (GMT). No. of bitstreams: 1 Denise Torreao Correa da Silva.pdf: 13435475 bytes, checksum: 0ee13ef29957b217cb6d5b50c30944cf (MD5) Previous issue date: 2016-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To estimate the measurement uncertainty of the pure-tone audiometry by air-conduction, in the frequencies from 250 Hz to 8000 Hz, and bone-conduction, at frequencies of 500 Hz to 4000 Hz. Method: This is an observational, descriptive and cross sectional study. Accuracy measurement tests under repeatability conditions were conducted (same measurement procedure, operator, measuring system, operating conditions and site, in a short time interval). Each of the nine participants took part in two trials with five repetitions each through air and bone conduction, in the right and left ear. In Trial 1 the interval between each repetition was five minutes. In Trial 2 the interval between repetitions was sixty minutes. To calculate the combined uncertainty the type A uncertainty, derived from repeatability, and Type B uncertainty derived from the audiometer calibration certificate, the audiometer resolution, and the conditions of the test environment were considered. Results: There was no statistically significant difference intra-individuals in different time intervals (p> 0,05), in both air and bone conduction. The median of type A uncertainty ranged from 0 dB to 2,7 dB in the right ear, and 0 dB to 3,5 dB in the left ear for air conduction. In bone conduction the median of type A uncertainty ranged from 2.2 dB to 2.7 dB in both ears. Type B uncertainties, for air and bone conduction, derived from the contribution of the equipment used for the test (0,4 dB), of the equipment resolution (1,4 dB), and the test environment (5,0 dB). Considering the median of type A uncertainty derived from accuracy measurement, and type B uncertainties mentioned above, the estimated of measurement uncertainty of pure tone audiometry, air and bone conduction, in this study, for the confidence level of 95% (k=1.96) and 95.45% (k=2.0) were 10 dB or 11 dB, for the frequencies tested, in both Trials 1 and Trial 2, in both ears. Conclusions: This study demonstrates the feasibility of accuracy measurement tests under repeatability conditions, as proposed in this work. In this study the contribution of type B uncertainties, derived from the audiometer calibration certificate, potentiometer and test environment, this latter being more prevalent, was higher than that of type A uncertainty derived from repeatability, indicating the need to keep control of these variables. The expression of measurement uncertainty can increase even more the sensitivity and specificity of audiometry, respectively increasing the rate of true positives and true negatives, since it is considered the gold standard. In this study the expanded uncertainty, for the confidence level of 95% and 95,45% ranged between 10 and 11 dB, in air and bone conduction. The reliability of the pure-tone audiometry test depends on the expression of its uncertainty; only so results obtained with the same subject in different places and times can be compared. Therefore the expression of uncertainty should be taken into consideration when delivering results and in preparing reports, for subsidizing decisions on hearing aids prescription, selection and adaptation procedures, as well as assessment of social security benefit payments, labor actions and health surveillance actions / Estimar a Incerteza de Medição no exame de audiometria tonal por via aérea, nas frequências de 250 Hz a 8 000 Hz, e por via óssea, nas frequências de 500 Hz a 4 000 Hz. Método: Nesta pesquisa, de natureza observacional, descritiva e transversal, foram realizados ensaios de precisão de medição sob condições de repetibilidade (mesmo procedimento de medição, operador, sistema de medição, condições de operação e mesmo local, em curto intervalo de tempo). Cada um dos nove participantes realizou dois ensaios, com cinco repetições de audiometria cada, por vias aérea e óssea, orelhas direita e esquerda. No Ensaio 1 o intervalo entre cada repetição foi de cinco minutos. No Ensaio 2 o intervalo entre as repetições foi de sessenta minutos. Para cálculo da incerteza padrão combinada considerou-se a incerteza do tipo A, derivada da repetibilidade, e as incertezas do tipo B, derivadas do certificado de calibração do audiômetro, da resolução do audiômetro, e das condições do ambiente de teste. Resultados: Para as vias aérea e óssea não houve diferença estatisticamente significante intraindivíduos nos diferentes intervalos de tempo (p > 0,05). A mediana da incerteza do tipo A variou de 0 dB a 2,7 dB, na orelha direita, e de 0 dB a 3,5 dB na orelha esquerda, para a via aérea. Na via óssea a mediana da incerteza do tipo A variou de 2,2 dB a 2,7 dB, em ambas as orelhas. As incertezas do tipo B, tanto para via aérea quanto para a via óssea, foram derivadas da contribuição do equipamento utilizado para o exame (0,4 dB), da resolução do equipamento (1,4 dB), e do ambiente de teste (5,0 dB). Levando-se em consideração a mediana das incertezas do tipo A e as incertezas do tipo B citadas acima, a estimativa da incerteza de medição da audiometria tonal por vias aérea e óssea, neste estudo, para os níveis da confiança de 95% (k=1,96) e 95,45% (k=2,0), foi de 10 dB ou 11 dB, nas frequências testadas, tanto no Ensaio 1 quanto no Ensaio 2, em ambas as orelhas. Conclusões: Este estudo demonstra a viabilidade de ensaios de precisão de medição sob condições de repetibilidade, conforme proposto neste trabalho. Neste estudo a contribuição das incertezas do tipo B, derivadas do certificado de calibração do audiômetro, do potenciômetro e do ambiente de teste, preponderando esta última, foi maior do que a incerteza do tipo A, derivada da repetibilidade, indicando a necessidade de manter-se controle sobre estas variáveis. A expressão da incerteza de medição da audiometria pode elevar, ainda mais, a sensibilidade, e a especificidade da audiometria, respectivamente aumentando a taxa de verdadeiros positivos e de verdadeiros negativos, uma vez que é considerada padrão ouro. Neste estudo a incerteza de medição expandida, para os níveis da confiança de 95% e 95,45% variou entre 10 dB e 11 dB, tanto para via aérea quanto para via óssea. A confiabilidade do exame de Audiometria Tonal, ou Audiometria de Tons Puros depende da expressão de sua incerteza; somente assim resultados obtidos com o mesmo sujeito, em locais e épocas diferentes, podem ser comparados. Portanto a expressão da incerteza deve ser levada em consideração quando da entrega de resultados e confecção de relatórios, seja para decisão sobre procedimentos de indicação, seleção e adaptação de aparelhos de amplificação sonora individual, assim como para avaliação de concessão de benefícios previdenciários, ações trabalhistas e ações de vigilância em saúde

The presented master’s thesis deals with the acoustics, specifically with the selected characteristics of the sound. It focuses on the anatomy of the auditory system and its function. The work describes the testing approaches for an evaluation of the auditory organ function and introduces modern methods used for the hearing tests, especially pure tone audiometry. A part of the thesis is dedicated to a concept of an audiometer for pure tone audiometry, which is presented in a detailed block diagram along with a description of its working components. Included chapters describe the partial circuits of the audiometer supplemented by the calcuations of its individual elements. The concluding part of the thesis deals with the evaluation of the device’s functionality.

Traffic is a complex environment in which many actors take part; several new technologies bring promises of reducing this complexity. However, cyclists—a particularly vulnerable road user group—have so far been somewhat put aside in these new developments, among them being Cooperative Intelligent Traffic Systems (C-ITS) and their aspects of human–computer interaction. This master’s thesis of industrial design engineering presents five multimodal collision warning signals for cyclists—future ones in these supposed C-ITS—using a novel application of bone conduction headphones (BCH) via sensations of both sound and touch. The thesis project was conducted as a complementary subset of the larger research project ‘V2Cyclist’ orchestrated by RISE Interactive. V2Cyclist set out to adapt the wireless V2X-protocol for cyclists by developing a physical prototype in the form of a bicycle helmet and corresponding human–computer interface. A significant part of the theoretical framework for this thesis was multiple resource theory: tasks in a different modality can be performed more effectively than in one already taxed attentively. Literature on human factors was also applied, particularly with regards to the perception of sound; evidence suggests that humans evolved a perceptual bias for threatening and ‘looming’ sounds that appear to encroach our peripersonal space; ethological findings point toward the association with low-frequency sounds to largeness. Sound design techniques usually applied to more artistic ends, such as synthesis and mixing, were repurposed for the novel, audiotactile context of this thesis. The thesis process was rooted in design thinking and consisted of four stages: context immersion, ideation, concept development, and lastly evaluation; converging and diverging the novel design space of using BCH in an audiotactile, i.e. bimodal way. The divergent approach generated a wide range of ideas. The later convergent approach did not result in one, definite design as further evaluation is required but also due to unknowns in terms of future hardware and network constraints. Given the plurality and diversity of cyclists, it may well follow that there is no optimal collision warning design in the singular. Hence, a range of five different solutions is presented. Each of the five multimodal collision warnings presents a different approach to conveying a sense of danger and urgency. Some warning signals are static in type, while others are more dynamic. Given the presumed rarity of collision warnings, multiple design techniques and rationales were applied separately, as well as in combination, to create different warning stimuli that signaled high urgency in an intuitive way. Namely, the use of: conventions in design and culture; explicitness in the form of speech; visceral appeal via threatening and animalistic timbres; dynamic and procedurally generated feedback; multimodal salience; crossmodal evocation of ‘roughness;’ size-sound symbolism to imply largeness; and innately activating characteristics of looming sounds. / Trafiken är en komplex miljö med många deltagare; diverse ny teknik gör anspråk på att underlätta denna komplexitet. Men, cyklister—en särskilt utsatt grupp av trafikanter—har hittills hamnat i skymundan för sådana utvecklingar. Vidare, aspekten av användbara gränssnitt för cyklister inom sådana uppkopplade och samverkande trafiksystem (C-ITS) har utforskats desto mindre. Det här examensarbetet inom Teknisk design presenterar fem multimodala kollisionsvarningar avsedda för cyklister—framtida sådana i dessa C-ITS—genom en ny och bimodal användning av benledande hörlurar via både ljud och vibrationer. Examensarbetet genomfördes i koppling till forskningsprojektet V2Cyclist, orkestrerat av RISE Interactive, vars projektmål var att anpassa det trådlösa kommunikationsprotokollet V2X för cyklister via en fysisk prototyp i form av en cykelhjälm och parallellt utveckla ett tillhörande användargränssnitt. En viktig del av det teoretiska ramverket för det här examensarbetet grundar sig på multiple resource theory: uppgifter kan utföras mer effektivt i en annan modalitet än i en som redan är belastad med uppmärksamhet. Mänskliga faktorer och teori om vår uppfattning användes; bevis pekar på att människor har evolutionärt utvecklat en bias för hotande ljud som upplevs inkräkta på vårt närmsta personliga revir; etologiska rön visar på en koppling mellan lågfrekventa ljud och ‘storhet.’ Tekniker inom ljuddesign vanligtvis använda till mer artistiska ändamål, såsom syntes och mixning, användes här till godo för att utforska den nya och bimodala designrymden. Processen för arbetet grundade sig i design thinking och bestod av fyra faser: kontextfördjupning, idégenerering, konceptutveckling, och utvärdering. En ny och tidigare outforskad designrymd beståendes av en bimodal, ljudtaktil användning av benledande hörlurar divergerades och konvergerades. Ett initialt utforskande angreppssätt gav upphov till en bred mängd av idéer. Ett senare renodlande angreppssätt gick, dock, inte hela vägen till endast en optimal lösning, då vidare utvärdering krävs men också på grund av okända teknologiska begränsningar. Dessutom, givet cyklisters stora mångfald, kan det möjligtvis följa att det inte finns någon enskild design av den optimala kollisionsvarningen. Ett spann på fem olika lösningar presenteras därmed. Fem koncept för multimodala kollisionsvarningar presenteras där varje variant uttrycker fara och kritiskhet på olika sätt. Vissa är statiska i typ, medan andra verkar mer kontinuerligt och dynamiskt. Det antogs att kollisionsvarningar sker sällan. Olika designtekniker och motiveringar har använts, ibland i kombination med varandra, för att skapa kollisionsvarningar vars avsikter omedelbart förstås: normer inom design och kultur gällande ljud; uttalad kommunikation i form av tal; anspråk på människors biologiska intuition via hotfulla och djurliknande klangfärger; dynamisk och procedurellt genererad feedback; multimodal effektfullhet; korsmodal känsla av grova texturer; size-sound symbolism för att antyda ‘storhet;’ samt de naturligt aktiverande egenskaperna hos looming sounds.