Age affects hearing and cognitive abilities. Older people, with and without hearing impairment (HI), exhibit difficulties in hearing speech in noise. Elderly individuals show greater difficulty in segregating target speech from distracting background noise, especially if the noise is competing speech with meaningful contents, so called informational maskers. Working memory capacity (WMC) has proven to be a crucial factor in comprehending speech in noise, especially for people with hearing loss. In auditory scenes where speech is disrupted by competing speech, high WMC has proven to facilitate the ability to segregate target speech and inhibit responses to irrelevant information. People with low WMC are more prone to be disrupted by competing speech and exhibit more difficulties in hearing target speech in complex listening environments. Furthermore, elderly individuals with a HI experience more difficulties in switching attention between wanted and irrelevant stimuli, and they employ more resources and time to attend to the stimuli than do normally - hearing (NH) younger adults. This thesis investigated the importance of inhibitory control and WMC for speech recognition in noise, and perceived listening effort. Four studies were conducted. In the first study, the aim was to develop a test of inhibitory control for verbal content, and to investigate the relation between inhibitory control and WMC, and how these two abilities related to speech recognition in noise, in young normally – hearing (YNH) individuals. In the second study we aimed to investigate the same relationship as in the first study to further strengthen the validity of the inhibitory test developed, as well as the importance of lexical access. It was also an aim to investigate the influence of age and hearing status on lexical access and WMC, and their respective roles for speech recognition in noise in both YNH and elderly HI (EHI) individuals. Study one and two showed that, for YNH, inhibitory control was related to speech recognition in noise, indicating that inhibitory control can help to predict speech recognition in noise performance. The relationship between WMC and speech recognition in noise in YNH shifted in the studies, suggesting that this relationship is multifaceted and varying. Lexical access was of little importance for YNH, although for EHI individuals, both WMC and lexical access was of importance for speech recognition in noise, suggesting that different cognitive abilities were of importance for the YNH and EHI individuals Study three investigated the relationship between inhibitory control, WMC, speech recognition in noise, and perceived listening effort, in YNH and elderly, for their age, NH, individuals (ENH). In study four the same relationships as in study three were investigated, albeit in EHI individuals. Two speech materials with different characteristics, masked with four background noises were used. The results in study three showed that less favourable SNRs were needed for informational maskers than for maskers without semantic content. ENH individuals were more susceptible to informational maskers than YNH individuals. In contrast, in study four, more favourable SNRs were needed for informational maskers. In both studies, results showed that speech recognition in noise performance differed depending on the characteristics of the speech material. The studies showed that high WMC, compared to low WMC, was beneficial for speech recognition in noise, especially for informational maskers, and resulted in lower ratings of perceived effort. Varying results were found in study three and four regarding perceived effort and inhibitory control. In study three good inhibitory control was associated with lower effort rating, while in study four, individuals with a HI and good inhibitory control rated effort as higher. The results suggest that hearing status, age, and cognitive abilities, contribute to the differences in performance between YNH, ENH, and EHI individuals in speech – recognition – in – noise - and cognitive tasks. This thesis has, for the first time, demonstrated that a measure of inhibitory control of verbal content, is related to speech recognition in noise performance in YNH, ENH and EHI individuals. Results presented in this thesis also show that both WMC and inhibitory control are related to an individuals’ perception of how effortful a listening task is. It also adds to the literature that WMC is related to speech recognition in noise performance for ENH and EHI individuals, but that this relationship is not as robust in YNH individuals. / Ålder påverkar hörseln och de kognitiva förmågorna. Äldre personer, med och utan hörselnedsättning, uppvisar ofta svårigheter att höra tal i miljöer med bakgrundsljud. De uppvisar större svårigheter att urskilja en måltalare, speciellt om det omgivande ljudet består av annat tal med meningsfullt innehåll, så kallad informationsmaskering. Arbetsminne har visat sig vara en viktig faktor för att förstå tal – i – brus, framför allt för personer med hörselnedsättning. I ljudmiljöer där tal störs av andra talkällor är hög arbetsminneskapacitet av vikt för att understödja förmågan att urskilja måltalaren från de störande talkällorna genom att underlätta inhiberingen av irrelevant information. Individer med lägre arbetsminneskapacitet är mer benägna att störas av andra talkällor, och har svårare att uppfatta måltalaren i komplexa lyssningssituationer. Vidare upplever äldre personer med hörselnedsättning att det är svårare att skifta uppmärksamheten mellan relevant och irrelevant stimuli, och de använder mer resurser och tid till omgivande stimuli än, ex. yngre individer med normal hörsel. I den här avhandlingen undersöktes vikten av inhibitionskontroll och arbetsminne vid taluppfattning i brus och upplevelsen av lyssningsansträngning. Fyra studier genomfördes. Syftet med första studien var att utveckla ett test för verbal inhibitionskontroll, och att undersöka relationen mellan inhibitionskontroll, arbetsminneskapacitet, och deras koppling till taluppfattning i brus hos yngre normalhörande personer. I studie två undersöktes ovanstående relationer för att vidare styrka validiteten för testet av inhibitionskontroll, samt vikten av lexikal åtkomst. Vidare syfte var att undersöka ålderns och hörselns inverkan på lexikal åtkomst och arbetsminneskapacitet, och deras respektive roller för taluppfattning i brus hos både yngre normalhörande och äldre hörselnedsatta personer. Studie ett och två visade att inhibitionskontroll var relaterad till taluppfattning i brus för yngre normalhörande personer, vilket indikerar att inhibitionskontroll kan användas för att underlätta att förutsäga förmågan att uppfatta tal – i – brus. Relationen mellan arbetsminneskapacitet och taluppfattning i brus hos yngre normalhörande var inte solid, vilket tyder på att relationen är mångsidig och skiftande. Lexikal åtkomst var av mindre betydelse för yngre normalhörande personer, ehuru hos äldre hörselskadade personer var både arbetsminneskapacitet och lexikal åtkomst viktigt för taluppfattning i brus. Detta tyder på att olika kognitiva förmågor var betydelsefulla för taluppfattningen i brus för yngre normalhörande och äldre hörselskadade personer. Studie tre undersökte relationen mellan inhibitionskontroll, arbetsminneskapacitet, taluppfattning i brus, och upplevd lyssningsansträngning hos yngre och äldre, för sin ålder, normalhörande personer. Två talmaterial med olika karakteristika användes och maskerades med fyra olika bakgrundsbrus. Resultatet visade att mindre gynnsamma signal – brus - förhållanden uppnåddes när informationsmaskering användes jämfört med brus utan semantiskt innehåll. Äldre normalhörande personer var mer mottagliga för informationsmaskering än yngre normalhörande personer. Hög arbetsminneskapacitet och god inhibitionskontroll var förmånliga för taluppfattning i brus, och resulterade i mindre upplevd lyssningsansträngning, jämfört med personer med lägre arbetsminneskapacitet och sämre inhibitionskontroll. Resultaten talar för att åldersrelaterade tillbakagångar i hörförmåga och, vissa, kognitiva förmågor, bidrar till skillnaderna i prestation mellan yngre och äldre normalhörande personer när det gäller förmågan att uppfatta tal - i - brus. Studie fyra undersökte samma relationer som i studie tre, ehuru hos äldre personer med mild – måttlig sensorineural hörselnedsättning. Resultaten visade att förmågan att uppfatta tal - i - brus varierade beroende på talmaterialets karakteristika, samt vilket bakgrundsbrus som användes. Hög arbetsminneskapacitet och god inhibitionskontroll var fördelaktiga för taluppfattningen, i synnerhet när informationsmaskering användes. Personer med högt arbetsminne upplevde mindre lyssningsansträngning, medan god inhibitionskontroll associerades med högre upplevd lyssningsansträngning. I föreliggande avhandling har det, för första gången, påvisats att verbal inhibitionskontroll relaterar till förmågan att uppfatta tal – i – brus hos yngre och äldre normalhörande, och äldre personer med hörselnedsättning. Resultaten som presenterats i avhandlingen visar att både arbetsminneskapacitet och inhibitionskontroll är associerade med en individs upplevelse av hur ansträngande en lyssningssituation är. Avhandlingen stödjer även tidigare forskning som visar på att arbetsminneskapaciteten är relaterad till förmågan att uppfatta tal – i – brus hos äldre  normalhörande, och äldre hörselskadade personer, men att denna relation inte är lika solid för yngre normalhörande personer.

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.

Ce travail s’est intéressé au traitement sous cortical de la parole dégradée par le bruit, notamment par la caractérisation première de l’importance de certains traits acoustiques dans la perception de la parole normale. Pour cela, nous avons d’abord participé à la mise au point de la technique électrophysiologique de potentiels évoqués auditifs obtenus en réponse à des sons de parole, technique proche de celle des potentiels évoqués auditifs précoces, mais qui a des exigences propres en matière de traitement du signal et de techniques de recueil, qui nécessitent une adaptation importante de part la nature différente des stimuli français par rapport aux stimuli anglais utilisés par l’équipe de référence américaine. Les différents axes de notre recherche ont, par ailleurs, permis de mettre en évidence l’importance de l’encodage sous cortical de certaines caractéristiques acoustiques telles que l’enveloppe temporelle, le voisement, mettant par là même en évidence un possible effet corticofuge sur l’encodage de celui-ci. Ces différentes expériences nous ont amenés à nous poser la question des conditions idéales de recueil des PEASP, et notamment l’effet de l’intensité sur le recueil de ceux-ci, mettant en évidence une relation non-linéaire entre l’intensité de stimulation, et les caractéristiques des PEAPSP. Si une intensité de 20 dB SL semble nécessaire au recueil d’un PEAPSP, les réponses montrent une variabilité qui reste très grande à l’échelon individuel, ce qui rend l’utilisation de l’outil PEAPSP à visée diagnostique, que ce soit dans les troubles du langage chez l’enfant, ou dans les troubles de l’audition dans le bruit, difficile. / The major purpose of my thesis was the investigation of brainstem structures implications into speech in noise processing, particularly by identifying the impact of acoustic cues on normal speech perception. Firstly, we were involved in the engineering of the speech auditory brainstem responses (SABR) recording system. SABR are similar to brainstem auditory evoked responses to clicks, but require different acquisition and signal processing set-ups, due to the difference between the French and the American stimuli used by the American reference team. The different studies presented here, permitted to emphasize the role of brainstem structures into the subcortical processing of acoustical cues, such as the temporal enveloppe, or the voicing, with a possible evidence of a corticofugal effect on SABR. These experimentations lead us to a more fundamental question on the best conditions required for PEASP collection, in particular, the best stimulation intensity needed. The results of the experiment on intensity effect showed a non linear relation between the stimulation intensity and PEASP characteristics. Even if an intensity of only 20 dB SL seems enough for SABR recording, individual results are still highly variable so that diagnostic application of SABR on, for example, children with language learning problems or subject suffering from speech in noise perception impairment remains difficult.

In this thesis, the relationship between cognition and speech-in-noise recognition, in normally-hearing Swedish students, is examined. The Trail Making Test, hypothesized to measure a wide range of cognitive functions, including executive function and working memory, has been criticized for being a culturally biased measure, hence the need for a culturally unbiased version. A between-group experiment was conducted in which a non-semantically dependent version of the Trail Making Test was compared to the original Trail Making Test in order to test for psychometric equivalence. A total of 21 young normally-hearing Swedish students were given three tests: TMT or TMT (non-semantically dependent version), a Swedish Reading Span Task and a Swedish speech-in-noise recognition task. The B parts of the two Trail Making Test versions differed significantly and both were moderately to highly correlated to speech-in-noise and reading span performance. The results indicates that the original Trail Making Test is a more plausible index for executive function and strengthens the relationship between executive function, working memory and speech-in-noise recognition.

L'objectif de cette thèse est de s'intéresser à l'impact de la dégradation du signal de parole sur le traitement et les représentations du langage. Le signal peut être dégradé de façon transitoire (i.e., parole dans le bruit, Axe 1) ou permanente (Axe 2). L'Axe 1 étudie l'impact de la présence de bruit sur le traitement sémantique au niveau du mot isolé et dans un contexte phrastique. Deux études ont permis de mettre en évidence que lorsque le signal de parole est masqué, le traitement sémantique est moins efficace, voire disparait. A la lumière de l'Effortfulness Hypothesis nous suggérons que le traitement sémantique n'est pas automatique mais dépendant de ressources cognitives. Lorsque le signal de parole est dégradé ces ressources cognitives sont allouées aux traitements linguistiques de bas niveau, les traitements de haut niveau comme le traitement sémantique sont donc moins efficaces. L'Axe 2 évalue les liens entre la dégradation permanente du signal de parole du fait d'un manque de maturité des traitements auditifs centraux ou à un Trouble du Traitement Auditif (TTA) et les représentations langagières. Deux études se sont intéressées au développement des traitements auditifs et à la présence de TTA au sein d'une population d'adultes dyslexiques. Les résultats ont mis en évidence que les traitements auditifs centraux continuent leur maturation durant l'adolescence. La dernière étude a permis de mettre en évidence chez la population dyslexique des difficultés dans les tests impliquant des traitements spectral et temporel. Ces compétences sont apparues liées au sein de cette population aux représentations phonologiques. L'ensemble des résultats suggèrent que la dégradation du signal de parole a différents effets sur le langage selon sa nature. Ainsi, lorsqu'elle est transitoire elle impacte sa compréhension en dépit d'une intelligibilité préservée. Une dégradation transitoire impacte la compréhension malgré l'intelligibilité, la dégradation permanente impacte les représentations différemment selon la population / This thesis aims at investigating the effect of speech degradation on language processing and representation. Speech signal can be degraded temporary (i.e., speech in noise) or continually, when central auditory processes are deficient. Experimental work was therefore based on two main axes. The first one got interested in the effect of noise on semantic processing, despite preserved intelligibility. Two studies showed that semantic processing is less efficient when speech is presented in noisy condition. In light of the Effortfulness Hypothesis, we suggest that semantic processing relies on cognitive resources. When signal is degraded these resources are reallocated to low level processes and therefore few are left available to perform higher level processes. Axe 2 aims at evaluating links between continuous speech degradation because of immaturity of central auditory processes or Auditory Processing Disorder (APD) and language representation. Two studies investigated the effect of auditory processing development on language on a children population (6-11 years old) and the effect of APD on language representation in an adult dyslexic population. Both populations were evaluated using the BECAC (Donnadieu et al. 2014). This battery aims at evaluating central auditory processes using non-verbal material so that auditory performances can be related to language competences. Results evidenced that central auditory processes mature until adulthood, and at some point in development (8-9 years old) are linked to language representation. Results of the last study showed that dyslexic adults are impaired in tests involving spectral and temporal processes; in addition these abilities are related with phonological awareness. Altogether, these results indicate that speech degradation has distinct effects on language depending on its nature. Therefore when temporary, speech degradation impacts its comprehension despite intelligibility. When continuous, speech degradation’s impact evolves during development and disappears in normal adults. However, it stays for dyslexics

Speech audiometry is considered an essential tool in the assessment of hearing, not only to validate pure tone measurements, but also to indicate speech perception as a critical communicative function. The use of sentence material in the assessment of speech perception has great value as it simulates – more closely than single words – the type of speech stimuli that listeners are confronted with on a daily basis. In South Africa, speech recognition (reception and discrimination) abilities are most commonly assessed through the use of single words, presented by monitored live voice, a practice sternly criticized in the literature. Furthermore, speech recognition is commonly evaluated in an ideal (quiet) listening environment. This method gives an incomplete impression of a patient’s auditory performance, since everyday listening situations are often characterised by the presence of background noise that influences comprehension of speech. The present study was therefore launched with the aim to develop a reliable measure of speech recognition in noise using Afrikaans sentence material. The development of the test was conducted in three phases. The first phase entailed the compilation of culturally valid, pre-recorded Afrikaans sentence material. During the second phase the uniformity of the recorded sentence collection was improved by determining the intelligibility of each sentence in the presence of noise and eliminating sentences that were not of equivalent difficulty in this regard. The objective of the third phase was to arrange the sentence material into lists using two different methods of list compilation. The first method involved grouping sentences together based solely on their intelligibility in noise (as assessed in the previous phase). The second method was the well-documented method of compiling phonetically balanced lists. The inter-list reliability of both sets of lists was evaluated in both normal hearing listeners and listeners with a simulated high frequency hearing loss. The results provided valuable information on the process of developing a test of speech recognition in noise, especially in terms of options for list compilation. Findings indicated that lists compiled according to intelligibility in noise showed a higher degree of equivalence than phonetically balanced lists when applied to normally hearing listeners. However, when applied to listeners with a simulated loss, phonetically balanced lists displayed greater equivalence. The developed test provides a means of assessing speech recognition in noise in Afrikaans, and shows potential for application in the assessment of hearing impaired populations, individuals with auditory processing difficulties, and the paediatric population. In addition, the methodology described for the development of the test could provide a valuable guideline for future researchers looking to develop similar tests in other languages. / Dissertation (MCommunication Pathology)--University of Pretoria, 2008. / Speech-Language Pathology and Audiology / MCommunication Pathology / Unrestricted

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations.

Background: The difficulties for people to understand and perceive speech in second languages in the presence of background noise is well documented in the literature. Similar difficulties have been reported in bilinguals. Consequently, the speech-in-noise tests can be used as a diagnostic tool to assess an individual's speech perception in noisy environments and plan effective hearing rehabilitation but it has less precision in the case of people whose first language is different from the tested language. On the other hand, the newly developed Situated Phoneme Test (SiP) might be a promising diagnostic method for evaluating speech perception in noise. The advantage is that the test person does not have to repeat the words as in the TiB test - something that makes it difficult for people with a different first language - and therefore the source of error of subjective assessment by the audiologist is eliminated. Aim: The aim of the present work is to evaluate the effectiveness of the SiP-test, for a group of people with Arabic as their first language, by examining the results of the SiP-test and the results of the conventional TiB test in relation to expected results for those who have Swedish as first language. A secondary aim is to evaluate people's experiences of using the TiB -test and the SiP-test. Materials and methods: Speech perception in noise was investigated in 32 normal-hearing individuals using the TiB test and the SiP-test. Common to all participants was that they had Arabic as their first language, moved to Sweden after the age of 8 and had good knowledge of the Swedish language according to the results of the language test they completed. The results of the TiB -test and the SIP-test were analyzed and compared with the expected values for people whose first language is Swedish. In addition, two diagnostic methods were evaluated by the participants using a questionnaire, specially designed for this purpose. Results: Overall, the SiP-test results for this group of people with Arabic as first language were similar or better (M = 83.1, SD = 4.31) than expected (M = 75, SD = 0) for those whose first language is Swedish, while the mean value for the TiB -test results was worse (M = 72.9, SD = 2.06) than expected (M = 84, SD = 0) for native Swedishspeakers. The TiB test results showed that no participant managed to reach the expected values based on people whose first language is Swedish. The individuals reported, with the use of a questionnaire, that the SiP-test was easier to perform (n = 18). Participants mentioned " the repeating of the words" as the more difficult for the TiB-test (n = 32) and "the use of the touch screen" as the easier for the SiP-test (n = 30). Conclusions: The results of the present study showed that SIP-test can be an accurate and reliable diagnostic method for the evaluation of speech perception in noise in non-native speakers, compared to the conventional TiB-test. SIP-test proved to be an easy, safe, realistic and objective diagnostic tool, based on the results and the reports of the participants who completed the test. Further research in individuals with various degrees and types of hearing loss, as well as similar studies in populations having other languages than the Arabic as its first language are needed in order to fully investigate the use and clinical applications of the SIP-test as a valuable part of an integral hearing investigation on the everyday clinical practice. / Bakgrund: Svårigheterna för personer att förstå och uppfatta tal på andraspråket i närvaro av bakgrundsbrus är väldokumenterade i litteraturen. Liknande svårigheter har rapporterats även hos tvåspråkiga. Följaktligen kan tal-i-brus-tester (TiB) användas som ett diagnostiskt verktyg för att bedöma en individs taluppfattning i bullriga miljöer och planera en effektiv hörselrehabilitering men det har mindre precision när det gäller personer som har ett annat förstaspråk än det testade språket. Det nyutvecklade Situated Phoneme Test (SiP) kan eventuellt vara en lovande diagnostisk metod för att utvärdera taluppfattning i buller. Fördelen med SiP-testet är att testpersonen inte behöver upprepa orden som i TiB-testet - något som gör det svårt för personer med ett annat förstaspråk - och därav elimineras felkällan av subjektiv bedömning från audionomen. Syfte: Syftet med denna studie är att utvärdera effektiviteten av SiP-testet, för en grupp av personer med arabiska som förstaspråk, genom att undersöka resultaten av SiP-testet och resultaten av det konventionella TiB-testet i relation till förväntade resultat för dem som har svenska som förstaspråk. Ett sekundärt syfte är att utvärdera personernas erfarenheter av att använda TiB-testet och SiP-testet. Metod och material: Taluppfattningen i brus undersöktes hos 32 normalhörande individer med hjälp av TiB-testet och SiP-testet. Gemensamt för samtliga deltagare var att de hade arabiska som förstaspråk, hade flyttat till Sverige efter 8 års ålder och hade goda kunskaper i det svenska språket enligt resultatet av det språktest de genomförde. Resultaten av TiB- och SiP-testerna analyserades och jämfördes med de förväntade värdena för personer som har svenska som förstaspråk. Dessutom utvärderades två diagnostiska metoderna av deltagarna med hjälp av ett frågeformulär, speciellt utformat för detta ändamål. Resultat: Sammantaget var SiP-testresultaten för denna grupp av personer med arabiska som förstaspråk liknande eller bättre (M = 83.1, SD = 4.31) än förväntat (M = 75, SD = 0) för de som har svenska som förstaspråk, medan medelvärdet för TiB-testresultaten var sämre (M = 72.9, SD = 2.06) än förväntat (M = 84, SD = 0) för de som har svenska som förstaspråk. TiB-testet resultatet visade att ingen deltagare lyckades nå de förväntade värdena baserade på personer som har svenska somförstaspråk. Flest av deltagarna rapporterade, genom frågeformuläret, att SiP-testet var lättare att utföra (n = 18). Deltagarna nämnde ”att upprepa orden" som det svårare för TiB-testet (n = 32) och "att använda pekskärmen" som det lättare för SiP-testet (n = 30). Slutsatser: Resultaten av den föreliggande studien visade att SiP-test kan vara en korrekt och tillförlitlig diagnostisk metod för att utvärdera taluppfattningen för personer med svenska som andraspråk. SiP-test visade sig vara ett enkelt, säkert, realistiskt och objektivt diagnostiskt verktyg, baserat på resultaten och rapporterna från deltagarna som genomförde testet. Ytterligare forskning på individer med olika grader och typer av hörselnedsättning, såväl som liknande studier i populationer som har andra språk än arabiska som sitt förstaspråk behövs för att fullständigt undersöka användningen och kliniska tillämpningar av SIP-testet som en värdefull del av en integrerad hörselundersökning om den kliniska vardagen.

Il est bien connu que les enfants qui présentent un trouble de traitement auditif (TTA) ont de la difficulté à percevoir la parole en présence de bruit de fond. Cependant, il n’existe aucun consensus quant à l’origine de ces difficultés d’écoute. Ce programme de recherche est consacré à l’étude des incapacités sous-jacentes aux problèmes de perception de la parole dans le bruit chez les enfants présentant un TTA. Le Test de Phrases dans le Bruit (TPB) a été développé afin d’examiner si les difficultés de perception de la parole dans le bruit d’enfants ayant un TTA relèvent d’incapacités auditives, d’incapacités cognitivo-linguistiques ou des deux à la fois. Il comprend cinq listes de 40 phrases, composées de 20 phrases hautement prévisibles (HP) et de 20 phrases faiblement prévisibles (FP), de même qu’un bruit de verbiage. Le niveau de connaissance du mot clé (mot final) de chaque phrase a été vérifié auprès d’un groupe d’enfants âgés entre 5 et 7 ans. De plus, le degré d’intelligibilité des phrases dans le bruit et le niveau de prévisibilité ont été mesurées auprès d’adultes pour assurer l’équivalence entre les listes. Enfin, le TPB a été testé auprès d’un groupe de 15 adultes et d’un groupe de 69 enfants sans trouble auditif avant de l’administrer à des enfants ayant un TTA. Pour répondre à l’objectif général du programme de recherche, dix enfants présentant un TTA (groupe TTA) et dix enfants jumelés selon le genre et l’âge sans difficulté auditive (groupe témoin) ont été soumis aux listes de phrases du TPB selon différentes conditions sonores. Le groupe TTA a obtenu des performances significativement plus faibles comparativement au groupe témoin à la tâche de reconnaissance du mot final des phrases présentées en même temps qu’un bruit de verbiage compétitif, aux rapports signal-sur-bruit de 0, +3 et +4 dB. La moyenne de la différence des scores obtenue entre les phrases HP et FP à chaque condition expérimentale de bruit était similaire entre les deux groupes. Ces résultats suggèrent que les enfants ayant un TTA ne se distinguent pas des enfants du groupe témoin au plan de la compétence cognitivo-linguistique. L’origine des difficultés d’écoute de la parole dans le bruit dans le cas de TTA serait de nature auditive. Toutefois, les résultats des analyses de groupe diffèrent de ceux des analyses individuelles. Les divers profils de difficultés d’écoute identifiés auprès de cette cohorte appuient l’importance de continuer les investigations afin de mieux comprendre l’origine des problèmes de perception de la parole dans le bruit dans le cas de TTA. En connaissant mieux la nature de ces difficultés, il sera possible d’identifier les stratégies d’intervention de réadaptation spécifiques et efficaces. / A hallmark listening problem of individuals presenting with Auditory Processing Disorder (APD) is their poor speech recognition in noise. The underlying cause of their difficulties in unfavourable listening conditions is unknown. The objective of this dissertation was to explore the underlying nature of the speech perception problems in noise in the case of APD. The Test de Phrases dans le Bruit (TPB) was developed to explore the underlying origins of the speech perception difficulties in noise in the case of APD, in order to identify if they are related to an auditory dysfunction, a language-based dysfunction or both. The TPB consists of five lists of 40 recorded sentences, including 20 highly predictable (HP) sentences and 20 low predictable (LP) sentences, and a speech babble. The familiarity of each sentence final key word was tested with a group of children from five to seven years old. The intelligibility in noise of the sentences and the degree of predictability were also measured with adult participants in order to obtain equivalent lists. The actual sentence list sets of the TPB have been tested with a group of 15 adults and a group of 69 children without any hearing problem before its use with children presenting with APD. To achieve the general goal of the study, ten participants identified with APD (APD group) were assessed with the TPB, as well as ten age and gender matched children with normal auditory processing functions (control group). The mean performances of the APD group were significantly lower than the ones of the control group on the TPB sentence keyword recognition in noise at the signal-to-noise ratios of 0, +3 and +4 dB. The group average of the HP and LP difference of scores was similar between the groups at each of the tested signal-to-noise ratio. These results suggest that, as a group, children with APD use linguistic contextual information when listening to speech in background noise to the same extent as the ones of the control group. According to these analyses, the underlying origin of the speech perception problems in noise in the case of APD would be related to an auditory dysfunction. However, examination of the group data analyses differed from the individual analyses. The verification of the individual patterns revealed different profiles suggesting that further substantiation of these preliminary findings is warranted. A better understanding of the listening difficulties in noise exhibited by individuals with APD should lead to specific and efficacious intervention programs.

Il est bien connu que les enfants qui présentent un trouble de traitement auditif (TTA) ont de la difficulté à percevoir la parole en présence de bruit de fond. Cependant, il n’existe aucun consensus quant à l’origine de ces difficultés d’écoute. Ce programme de recherche est consacré à l’étude des incapacités sous-jacentes aux problèmes de perception de la parole dans le bruit chez les enfants présentant un TTA. Le Test de Phrases dans le Bruit (TPB) a été développé afin d’examiner si les difficultés de perception de la parole dans le bruit d’enfants ayant un TTA relèvent d’incapacités auditives, d’incapacités cognitivo-linguistiques ou des deux à la fois. Il comprend cinq listes de 40 phrases, composées de 20 phrases hautement prévisibles (HP) et de 20 phrases faiblement prévisibles (FP), de même qu’un bruit de verbiage. Le niveau de connaissance du mot clé (mot final) de chaque phrase a été vérifié auprès d’un groupe d’enfants âgés entre 5 et 7 ans. De plus, le degré d’intelligibilité des phrases dans le bruit et le niveau de prévisibilité ont été mesurées auprès d’adultes pour assurer l’équivalence entre les listes. Enfin, le TPB a été testé auprès d’un groupe de 15 adultes et d’un groupe de 69 enfants sans trouble auditif avant de l’administrer à des enfants ayant un TTA. Pour répondre à l’objectif général du programme de recherche, dix enfants présentant un TTA (groupe TTA) et dix enfants jumelés selon le genre et l’âge sans difficulté auditive (groupe témoin) ont été soumis aux listes de phrases du TPB selon différentes conditions sonores. Le groupe TTA a obtenu des performances significativement plus faibles comparativement au groupe témoin à la tâche de reconnaissance du mot final des phrases présentées en même temps qu’un bruit de verbiage compétitif, aux rapports signal-sur-bruit de 0, +3 et +4 dB. La moyenne de la différence des scores obtenue entre les phrases HP et FP à chaque condition expérimentale de bruit était similaire entre les deux groupes. Ces résultats suggèrent que les enfants ayant un TTA ne se distinguent pas des enfants du groupe témoin au plan de la compétence cognitivo-linguistique. L’origine des difficultés d’écoute de la parole dans le bruit dans le cas de TTA serait de nature auditive. Toutefois, les résultats des analyses de groupe diffèrent de ceux des analyses individuelles. Les divers profils de difficultés d’écoute identifiés auprès de cette cohorte appuient l’importance de continuer les investigations afin de mieux comprendre l’origine des problèmes de perception de la parole dans le bruit dans le cas de TTA. En connaissant mieux la nature de ces difficultés, il sera possible d’identifier les stratégies d’intervention de réadaptation spécifiques et efficaces. / A hallmark listening problem of individuals presenting with Auditory Processing Disorder (APD) is their poor speech recognition in noise. The underlying cause of their difficulties in unfavourable listening conditions is unknown. The objective of this dissertation was to explore the underlying nature of the speech perception problems in noise in the case of APD. The Test de Phrases dans le Bruit (TPB) was developed to explore the underlying origins of the speech perception difficulties in noise in the case of APD, in order to identify if they are related to an auditory dysfunction, a language-based dysfunction or both. The TPB consists of five lists of 40 recorded sentences, including 20 highly predictable (HP) sentences and 20 low predictable (LP) sentences, and a speech babble. The familiarity of each sentence final key word was tested with a group of children from five to seven years old. The intelligibility in noise of the sentences and the degree of predictability were also measured with adult participants in order to obtain equivalent lists. The actual sentence list sets of the TPB have been tested with a group of 15 adults and a group of 69 children without any hearing problem before its use with children presenting with APD. To achieve the general goal of the study, ten participants identified with APD (APD group) were assessed with the TPB, as well as ten age and gender matched children with normal auditory processing functions (control group). The mean performances of the APD group were significantly lower than the ones of the control group on the TPB sentence keyword recognition in noise at the signal-to-noise ratios of 0, +3 and +4 dB. The group average of the HP and LP difference of scores was similar between the groups at each of the tested signal-to-noise ratio. These results suggest that, as a group, children with APD use linguistic contextual information when listening to speech in background noise to the same extent as the ones of the control group. According to these analyses, the underlying origin of the speech perception problems in noise in the case of APD would be related to an auditory dysfunction. However, examination of the group data analyses differed from the individual analyses. The verification of the individual patterns revealed different profiles suggesting that further substantiation of these preliminary findings is warranted. A better understanding of the listening difficulties in noise exhibited by individuals with APD should lead to specific and efficacious intervention programs.