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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Taluppfattning av enstaviga ord i stationärt brus med och utan top-down stöd. / Speech reception thresholds of monosyllabic words in noise with and without top-down support

Persson, Johan January 2012 (has links)
Teorier inom Kognitiv hörselvetenskap beskriver hur uppfattning av tal beror på två olika typer av processer. Bottom-up processer associeras med akustiska och fonetiska egenskaper hos en inkommande signal och top-down processer associeras med lexikala, syntaktiska, semantiska samt kontextuella egenskaper. Förmågan att utnyttja top-down processer tros bero på kapaciteten hos arbetsminnet. För att undersöka en skillnad mellan bottom-up och top-down samt deras förhållande till arbetsminnet har ett Speech-in-Noise (SIN) test utformats och genomförts på 15 försöksdeltagare. Testet undersöker skillnader i tröskelvärden för att identifiera ett enstavigt ord i ett uppåtgående förhållande till stationärt brus, mot tröskelvärden för att identifiera ett enstavigt ord i stationärt brus med hjälp att top-down stöd. Top-down stöd ges i form av explicit priming och undersöks i både uppåtgående och nedåtgående förhållande till bruset. Två typer av arbetsminnestest, ”Letter Memory Test” och ”Reading Span Test”, användes för att undersöka en korrelation med differenser mellan tröskelvärdena. Resultaten visade på en signifikant skillnad mellan vanliga tröskelvärden och tröskelvärden då explicit top-down stöd används. Någon signifikant korrelation mellan kapaciteten hos arbetsminnet och differenserna dessa tröskelvärden fanns inte.  Dock så fann analysen en signifikant korrelation mellan skillnad i tröskelvärden, för top-down stöd i uppåtgående och nedåtgående förhållande till brus, och ”Letter Memory Test”.
2

Monaural Speech-in-Noise Thresholds Using the Hearing in Noise Test (HINT)

Parrish, Denise 01 November 2003 (has links)
Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise. The purpose of this pilot study was to investigate monaural speech reception thresholds for sentences (RTS) in quiet and in noise using the standardized Hearing-in-Noise Test (HINT). Data was collected from one clinical setting using twenty-five subjects with bilateral normal hearing (WNL) and twenty subjects with bilaterally symmetrical sensorineural hearing loss (SNHL). Subject age ranged from 40 to 65 years. The study results were generally in agreement with the HINT norms. It was concluded that administering the HINT monaurally under headphones could differentiate between normal hearing individuals and individuals with cochlear hearing loss. The SNHL group exhibited higher RTSs than the WNL group in both quiet and in noise. The mean RTS difference between the two groups in quiet was 14.56 dB while the mean RTS difference in noise was only 2.85 dB. Surprisingly, the difference between the two subject groups in quiet was greater than was expected.
3

Towards the Development of the New Zealand Hearing in Noise Test (NZHINT)

Hope, Ruth Veronica January 2010 (has links)
The ability to understand speech in noise has a profound impact on everyday communication, but cannot be predicted on the basis of puretone thresholds and/or performance on tests of speech in quiet. The aim of this thesis was to develop an adaptive speech in noise test based on the Hearing in Noise Test (HINT) that would be reliable and valid for speakers of New Zealand English (NZE). The methodology used followed the standard procedures for developing the HINT in a new language. Five hundred sentences of 5-7 syllables were collected from New Zealand children’s books and recorded by a native NZE speaker. Nine normal-hearing native NZE speakers aged 18-50 listened to three sets of 50 sentences at -2, -4 and -7 dB signal-to-noise ratios (SNR) in order to establish a performance-intensity (PI) function for these sentences. Three groups of 10 participants were scored on their performance on the sentences in 65 dBA speech-weighted noise at varying SNR. After each round of testing with a new group of participants, the SNR of each sentence was adjusted in order to get closer to 70% intelligibility for all sentences. Sentences that were too easy or difficult or did not respond to adjustments were discarded. Once the remaining 240 sentences were of approximately equal intelligibility, 24 phonemically matched lists of 10 sentences were formed and tested on 12 participants using the adaptive HINT software. The overall mean threshold was calculated as -6 dB, s.d=1.1 dB. The lists were combined to form 12 lists of 20 sentences which would become the NZHINT. Time delays meant that the collection of normative data could not be completed.
4

Monaural speech-in-noise thresholds for sentences using the hearing in noise test (HINT) [electronic resource] / by Denise Parrish.

Parrish, Denise (Denise Lynn) January 2003 (has links)
Professional research project (Au.D.)--University of South Florida, 2003. / Title from PDF of title page. / Document formatted into pages; contains 25 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise. / ABSTRACT: The purpose of this pilot study was to investigate monaural speech reception thresholds for sentences (RTS) in quiet and in noise using the standardized Hearing-in-Noise Test (HINT). Data was collected from one clinical setting using twenty-five subjects with bilateral normal hearing (WNL) and twenty subjects with bilaterally symmetrical sensorineural hearing loss (SNHL). Subject age ranged from 40 to 65 years. The study results were generally in agreement with the HINT norms. It was concluded that administering the HINT monaurally under headphones could differentiate between normal hearing individuals and individuals with cochlear hearing loss. The SNHL group exhibited higher RTSs than the WNL group in both quiet and in noise. The mean RTS difference between the two groups in quiet was 14.56 dB while the mean RTS difference in noise was only 2.85 dB. Surprisingly, the difference between the two subject groups in quiet was greater than was expected. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
5

Normalisation, Evaluation and Verification of the New Zealand Hearing Screening Test.

Bowden, Alice Therese January 2013 (has links)
Presbycusis, or age-related hearing loss, is one of the most common chronic conditions to affect adults. On average individuals wait seven years from the time they notice a hearing impairment to the time they seek help from a hearing professional. This delay may have wide reaching implications for public health in the coming decades, as aging populations become more prevalent and as further research assesses the relationship between hearing loss and mental health conditions such as depression and dementia. The development of the New Zealand Hearing Screening Test (NZHST) aims to fulfil a need for a robust hearing screening test that individuals can access from home. This digit triplet test (DTT) will be particularly valuable for those in rural areas where audiological services are sparse and for those who have mobility issues which restrict attendance at clinical appointments. In order to accommodate as many New Zealanders as possible, the NZHST will have two versions, an internet version and a land-line telephone version; both of which can be delivered into their home in either New Zealand English or Te Reo Māori. This research is the third instalment in the development of the NZHST. The current research is divided into three parts; the verification of the New Zealand English DTT for the internet version, the pilot study for the Te Reo Māori DTT for the internet version, and the normalisation of the New Zealand English DTT for the telephone version. In the verification process, 50 individuals with various audiometric thresholds listened to 3 lists of 27 New Zealand English digit triplets, presented in three conditions; binaurally and to each ear separately via an internet interface. In the pilot study, 27 participants with various audiometric thresholds listened to 3 lists of 27 Te Reo Māori digit triplets via a software interface on a laptop computer. The normalisation process involved 10 individuals with normal hearing (average air-conduction pure tone thresholds of ≤ 20 dB HL) listening to 168 New Zealand English digit triplets under two different noise conditions; one as continuous speech noise and the other a noise with spectral and temporal gaps (STG noise) presented via a software interface on a laptop computer. Four conditions of the 168 digits were presented; once to each ear for the continuous noise, and once to each ear for the STG noise. Significant correlations were found between the binaural DTT and PTA (R = 0.66), and between the monaural ear DTT and PTA (R = 0.73) for the verification. The binaural DTT had a test sensitivity of 94% and a specificity of 88%. Pilot study correlation between binaural DTT and PTA was R = 0.61, and was R = 0.63 between monaural DTT and PTA; while the binaural sensitivity (100%) and specificity (100%) of the Te Reo DTT was affected by the very small number of participants with hearing loss (n = 4). The normalisation revealed that detection of the digit triplets was easier when STG noise (Lmid = -11.5 dB SNR, SD = 1.6 dB) was used as a masker, rather than continuous noise (Lmid = -8.9 dB SNR, SD = 1.4 dB).
6

Evaluating the Usefulness of an Aural Gapped Listening Summary as a Measure of Academic Listening Proficiency

Mottaghinejad, Sarah Elizabeth 09 July 2010 (has links) (PDF)
For this project I sought to find a more effective means of evaluating academic listening comprehension. This involved doing an in-depth investigation of academic listening, the constructs involved in listening comprehension, and of methods of assessing listening comprehension. It also included a study of the concept of test usefulness (Bachman and Palmer, 1996), which consists of reliability, construct validity, authenticity, interactiveness, impact, and practicality, and is used to help select the most effective methods of assessing language abilities. Based on my review of listening comprehension testing methods, I created a method of assessing academic listening comprehension, Aural Gapped Listening Summaries (AGLS), produced a short version of the AGLS for piloting through BYU's English Language Center and credit exam for matriculated students, and then analyzed the results of this piloting to determine whether future investigation was merited. This project write-up includes a description of the development of the AGLS, the methods of administration, and students' cursory perceptions of the AGLS, as well as the results of the pilot test. The AGLS involved students listening to an excerpt of a lecture followed by an aural summary of that lecture with every 8th word replaced by low-volume static. Then they were asked to type a word or phrase in a box on their computer screens that would best fill in the gap where the static was. Ranks on the AGLS were correlated with a standard listening test, which is administered every semester at Brigham Young University, and with students' individual perceptions of their listening abilities. Results showed that AGLS correlates moderately well with traditional measures of academic listening (r=0.7731) while giving testers interesting information about student interlanguage in very little time. Results further showed that AGLS has a much higher reliability coefficient (r=0.9223) in comparison to the other listening test. Therefore, although traditionally testers have had to write lengthy tests in order to get an adequate representation of students' listening abilities, it may be possible to obtain the necessary information about students' abilities with this more time-efficient measurement tool.
7

Developing a digits in noise screening test with higher sensitivity to high-frequency hearing loss

Motlagh Zadeh, Lina 02 August 2019 (has links)
No description available.
8

Sound source contributions for the prediction of vehicle pass-by noise

Braun, Michael E. January 2014 (has links)
Current European legislation aims to limit vehicle noise emissions since many people are exposed to road traffic noise in urban areas. Vehicle pass-by noise is measured according to the international standard ISO 362 in Europe. More recent investigations of urban traffic have led to the proposal of a revised ISO 362 which includes a constant-speed test in addition to the traditional accelerated test in order to determine the pass-by noise value. In order to meet the legal pass-by noise requirements, vehicle manufacturers and suppliers must analyse and quantify vehicle noise source characteristics during the development phase of the vehicle. In addition, predictive tools need to be available for the estimation of the final pass-by noise value. This thesis aims to contribute to the understanding of vehicle pass-by noise and of the characteristics of the vehicle noise sources contributing to pass-by noise. This is supported through an extensive literature review in which current pass-by noise prediction methods are reviewed as well. Furthermore, three vehicle noise sources are replicated experimentally under laboratory conditions. This involves an orifice noise source, represented by a specially designed loudspeaker on a moving trolley, shell noise, represented by a metal cylinder structure, and tyre cavity and sidewall noise, represented by an annular membrane mounted on a tyre-like structure. The experimentally determined directivity characteristics of the acoustically excited noise sources are utilised in the pass-by noise prediction method. The predictive results are validated against experimental measurements of the three vehicle-like noise sources made within an anechoic chamber.
9

Taluppfattning i ofördelaktiga förhållanden : Hur påverkar kognitiv förmåga perceptionen av enstaviga ord i brus bestående av talande röster?

Widman Börjesson, Sara January 2014 (has links)
Inom disciplinen kognitiv hörselvetenskap tillämpas en integrerad ansats där taluppfattning beskrivs ur både ett auditivt bottom-up-perspektiv och ett kognitivt top-down-perspektiv. Studien undersökte hur taluppfattning varierar med, respektive utan top-down-stöd och vad de kognitiva förmågorna uppmärksamhet, minne och inhiberingsförmåga hade för inverkan. Taluppfattningsförmåga utvärderades med hjälp av ett Speech-In-Noise-test (SIN-test) som bestod av tre deltest där enstaviga ord presenterades i en ofördelaktig miljö bestående av röster som talande i mun på varandra. I deltest 1 presenterades ord i uppåtgående förhållande till rösterna utan kognitivt stöd, i deltest 2 presenterades ord i nedåtgående förhållande till rösterna med kognitivt stöd och i deltest 3 presenterades ord i uppåtgående förhållande till rösterna med kognitivt stöd. Detta resulterade i identifiering av tre tröskelnivåer för taluppfattning. Kognitiva förmågor utvärderades med hjälp av Reading span test, Size Comparison span task (SIC-span) och Paced Auditory Serial-Addition Test (PASAT). Envägs variansanalys av taluppfattningstesten visade på signifikanta skillnader mellan alla tre testen. I test 2 identifierades lägst tröskelvärde, därefter test 3 och slutligen test 1. Korrelationsanalys visade på icke signifikanta samband mellan de tre SIN-testen. Av de kognitiva förmågorna och SIN- testen visade endast PASAT A på ett signifikant samband med SIN-test 2. Analys av de kognitiva förmågorna och differenserna mellan SIN-testen gav inga signifikanta samband. Slutligen vid analys av de kognitiva förmågorna hade PASAT A och PASAT B ett starkt positivt samband medan PASAT B och Reading span test hade ett starkt negativt samband. Resultaten i studien talade för att top-down-stöd ger bättre taluppfattningsförmåga och att uppmärksamhetskapacitet är en förmåga som har en signifikant inverkan på taluppfattning i nedåtgående förhållande till ett brus av röster.
10

Pass-by noise contribution analysis of electric vehicles

Falk Lissel, Linus January 2014 (has links)
In the modern urban lifestyle, more and more people are exposed to noise pollution in form of traffic noise. As a response to this, the automotive OEMs (Original Equipment Manufacturer) are put under pressure to reduce the emitted noise from vehicles. To be able to meet the upcoming, stricter regulations, the automotive OEMs seeks new techniques to be able to front load the pass-by noise engineering in the vehicle development process and to identify and understand the different sources that contributes to the exterior noise.Earlier exterior sources ranking using ASQ (Airborn Source Quantification) with an energetic approach during pass-by noise test has yielded very good and reliable results for an ICE (Internal Combustion Engine) vehicle.In this Master Thesis, two exterior source ranking methods have been tested and evaluated for an electric vehicle during in-room pass-by noise test. The two methods were: ASQ and OPA (Operational Path Analysis). In total, five models were built from the two methods and each model was evaluated for, in total, three driving conditions corresponding to the current ISO362-1:2007 and the proposed, revised version.The results show that the ASQ models are not capable to correctly estimate the engine contribution due to its high tonality. Moreover, it was seen that the energetic ASQ model is very sensitive to small changes. Both ASQ models underestimated the tire noise.The OPA model on the other hand managed to estimate the total contribution very well. Both the engine contribution and the tire contributions are well estimated. Nevertheless, OPA as method has several weaknesses and building an OPA model is not a straightforward task. Its weaknesses and the process to reach a final OPA model are discussed in this thesis.It was seen that one of the most crucial steps in an OPA model is to have clean references to get meaningful results. A MIMO-FIR filter was therefore used to filter out engine harmonics from the tire references. Its principles and importance for the end results are also discussed.Included is also an overview of the basic principles in TPA (Transfer Path Analysis), ASQ, OPA and in room pass by noise test as well as a description of the test campaign.

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