Highly directive loudspeakers have long been important tools for sound system designers, experimental acousticians, and many other professionals in the audio industry. They allow sound engineers to more easily manipulate the radiation pattern of their loudspeakers to accommodate the purpose of the venue. Many commercially available products, while exhibiting good directivity at mid and high frequencies, generally lack control in the low frequency range. A new method for controlling the radiation pattern of a loudspeaker at low frequencies has been developed and modeled extensively. Prototypes have been built and tested in an anechoic chamber. Results from computer modeling and experimental measurements will be presented and compared in this thesis.

Electropalatometry (EPM) has proven to be a useful clinical and research tool for measuring tongue-to-palate contact. The goal of this study was to determine whether the development of a database of standardized palatometric articulation files is feasible by examining the variability which exists within and between speakers. Twenty standard American English dialect speakers were fitted with palatometer pseudopalates. Test stimuli were VCV nonsense words using a schwa in the initial position, the 15 palatal consonants, and three corner vowels, /a/, /i/, /u/. From these palatometric recordings a variability index was created to examine intra- and interspeaker variability. Different aspects of articulation (i.e., place, manner, voicing, coarticulation) were considered. Significant findings for variability were found for place of articulation in the /i/ vowel context and for manner of articulation in the /ɑ/ vowel context. Also in the /a/ vowel context, significant findings were found between the commonly misarticulated /l/, /r/, and /s/. Consonants coarticulated with /a/ were found to be significantly less variable than consonants coarticulated with /u/. Also, speakers who were more variable in one vowel context, tended to be more variable in other vowel contexts. These quantitative findings, as well as qualitative observations, are discussed from theoretical and clinical perspectives. Directions for future research are outlined.

The purpose of this study was to examine how length and location of speech pausing affects a listeners' perception of likability and communication effectiveness. Furthermore, the end goal of this study is to understand how to better assess atypical speech pause for persons with aphasia (PWA). Speech samples were collected from two neurotypical speakers over the age of 75. The speech samples were the recorded responses of picture description tasks found in the Western Aphasia Battery (WAB) and the Boston Diagnostic Aphasia Examination (BDAE). These speech samples were then modified to include artificial pauses located both within sentence and between sentence, as well as differing lengths of three seconds, five seconds, and seven seconds. Forty-one listeners (31 female, 8 male) were recruited to listen to the 28 speech samples. Using a visual analogy scale, listeners rated each sample on their perception of likability and communication effectiveness. Communication effectiveness and likability ratings were significantly higher for between-utterance pauses. Likewise, ratings were highest for the baseline (no pause) stimuli and decreased as pause length increased. Across all conditions, ratings for the male speaker were rated slightly greater than that of the female speaker. Results of this study provide preliminary evidence that longer speech pause, especially found within utterance, affect the likability and communication effectiveness of PWA. It is hoped that additional research regarding speech pause will be conducted to determine how best to assess speech pause in PWA.

Orbit är en innovativ och tillgänglig högtalare för hemmet där upplevelse och funktion har varit kärnan i designen. Läran om ljud i rörelse kallat Kymatik har gett inspiration till att arbeta ur ett nytt perspektiv och gett ett nytt synsätt om hur ljudet rör sig. Högtalarkomponenterna har utformats med okonventionella former för att uppnå fler sätt att rikta ljud och ge uppfattningen om stort ljud från en kompakt högtalare. Miljö, erfarenhet och användare har beaktats för att skapa en långvarig användning av högtalaren. Det borde vara inspirerande och enkelt att komma närmare din musik i olika utrymmen. / Orbit is an innovative and accessible speaker for the home where experience and function have been the core of the design. The study of sound in motion called Cymatics has given inspiration to work from a new perspective and approach about how sound travels. The components of the speaker have been designed with unconventional shapes to achieve more ways of directing sound and give the perception of large sound from a compact speaker.  Environment, experience and users have been taken into consideration to create a long-term use of the speaker. It should be inspiring and easy to get closer to your music in different spaces.

Säkerhetsläget i Sverige och Europa är osäkert och ett allmänt behov av övervakning har ökat. Övervakningskameror kan både förhindra brott och lösa redan begångna brott. Axis Communication är världsledande inom nätverkskameror. Syftet med arbetet är att integrera högtalare och mikrofon i övervakningskameror. Målet är att till en ny övervakningskamera kunna lyfta in ett färdigt koncept, en audiomodul, med högtalare och mikrofon som passar givna krav på ljudkvalitet och ljudtryck. Val av koncept, högtalare och mikrofon, har genomomförts genom en noggrann produktutvecklingsprocess med delar som intern och extern sökning, utvärdering av lösningsvarianter, detaljutveckling och produkttestning. Ett koncept med integrerad högtalare och mikrofon har tagits fram. En högtalare har valts och placerats i väggen i kamerans innerchassi. En Smart Amp används för att högtalaren ska kunna spela så högt som möjligt utan att ljudkvalitén försämras. Mikrofonen placeras på kamerans ytterchassi så långt ifrån högtalare som möjligt och med en ljudisolerande kåpa för att undvika eko från högtalaren till mikrofonen. Arbetet resulterar i ett koncept med högtalare och mikrofon som uppnår på förhand uppställda krav på ljudtryck och ljudkvalité. Konceptet bidrar till en tryggare miljö genom att en snabbare detektion uppnås och bättre ljud leder till att meddelandeutskick blir lättare att höra. / The security situation in Sweden and Europe is uncertain and a general need for surveillance has increased. Surveillance cameras can both prevent crimes and resolve already committed crimes. Axis Communication is the world leader in network cameras. The purpose of the work is to integrate loudspeakers and microphones into surveillance cameras. The goal is for a new surveillance camera to lift a ready-made concept, an audio module, with speakers and microphones that meet the requirements for sound quality and sound pressure. Selection of concepts, speaker and microphone has been implemented through a careful product development process with parts such as internal and external search, evaluation of solution variants, detail development and product testing. A concept with integrated speaker and microphone has been developed. A speaker has been selected and placed in the camera's inner chassis. A Smart Amp is used to allow the speaker to play as loud as possible without impairing the sound quality. The microphone is placed on the camera's outer chassis as far away from the speaker as possible and with an acoustic cover to avoid echo from the loudspeaker to the microphone. The work results in a loudspeaker and microphone concept that meets prerequisites for sound pressure and sound quality. The concept contributes to a safer environment by achieving a faster detection and better sound, making public address messaging easier to hear.

<p> Listener vs. speaker-oriented speech: Studying the language of individuals with autism There are many mechanisms speakers utilize in conversation that aid a listener's understanding. However, there are also many characteristics of speech where it is unclear whether they serve listener or speaker-oriented functions. For example, speakers frequently produce disfluencies such as "um or "uh," which are helpful to listeners, indicating that the speaker is not finished speaking yet. We do not know, however, if these are used intentionally to aid listeners. In addition, the tendency to place animate items as sentential subjects may benefit either speaker or listener. Since individuals with autism engage in minimal listener-oriented behaviour, they are a useful group to differentiate these functions. Results showed that individuals with autism used fewer ums and uhs, and more silent pauses than controls, but used animacy similarly. This suggests that the use of ums and uhs is for the benefit of listeners, but the bias toward animate subjects is not.</p> / Thesis / Master of Science (MSc)

In my thesis I ask the epistemological question: If a speaker testifies to some proposition p to some hearer, and the hearer learns that p, must that speaker believe that p? Those who maintain the traditional view in the epistemology of testimony claim that testimony is primarily a way in which speakers transmit beliefs to hearers. If this is the case, then in order to transmit the belief that p, the speaker must be in possession of a belief that p. Other epistemologists reject this view altogether and argue that when speakers stand in the right sort of epistemic relation to the statements they issue they properly testify. My project carves out a position between these two views. I argue that speakers need not believe p, but speakers must be in some appropriate epistemic state with respect to p in order to properly testify to p. On my view, understanding is among the epistemic states that can place a speaker in the right sort of epistemic relation to p. Thus, if p is a consequence of a speaker's understanding of a subject, the speaker is licensed to testify that p. / Master of Arts

The present compilation thesis investigates the use of a pattern that is commonly found in academic writing, namely the introductory it pattern (e.g. it is interesting to note the difference). The main aim is to shed further light on the formal and functional characteristics of the pattern in academic writing. When relevant, the thesis also investigates functionally related constructions. The focus is on learner use, but reference corpora of published writing and non-native-speaker student writing have also been utilized for comparison. The thesis encompasses an introductory survey (a “kappa”) and four articles. The material comes from six different corpora: ALEC, BATMAT, BAWE, LOCRA, MICUSP and VESPA. Factors such as native-speaker status, discipline, level of achievement (lower-graded vs. higher-graded texts) and level of expertise in academic writing are investigated in the articles. In more detail, Articles 1 and 2 examine the formal (syntactic) characteristics of the introductory it pattern. The pattern is studied using modified versions of two previous syntactic classifications. Articles 3 and 4 investigate the functional characteristics of the pattern. In Article 3, a functional classification is developed and used to categorize the instances. Article 4 examines the stance-marking function of the pattern in relation to functionally related constructions (e.g. stance adverbs such as possibly and stance noun + prepositional phrase combinations like the possibility of). The introductory it pattern was found to be relatively invariable in the sense that a small set of formal and functional realizations made up the bulk of the tokens. The learners, especially those whose texts received a lower grade, made particularly frequent use of high-frequency realizations of the pattern. The thesis highlights the importance of not limiting investigations of this kind to comparisons across native-speaker status, as this is only one of the several factors that can influence the distribution. By exploring the potential importance of many different factors from both a formal and a functional perspective, the thesis paints a more complete picture of the introductory it pattern in academic writing, of use in, for instance, second-language instruction.

This thesis focused on students’ cognitive and affective responses to Arabic (L1) and English (L2) used by English as a Foreign Language (EFL) teachers who come from different L1 backgrounds in English (L2) classrooms in an English institute at a university in Saudi Arabia. Consideration of students’ responses to teachers’ use of English was crucial in this study as it helped to shed light on students’ cognitive and affective responses to the Arabic used by teachers. In addition, students’ preferences for EFL teachers in respect of their L1 background (native Arabic speaker teacher, native English speaker teacher and non-native English/Arabic speaker teacher) were examined. In order to be able to investigate the students’ responses and preferences, it was nessesary, firstly, to develop a deeper understanding of what they were responding to, namely the extent to which, and the conditions under which, teachers employ Arabic in the L2 classrooms. In addition, the extent to which teachers’ use of Arabic varies according to their students’ level of proficiency was also explored. Teachers' views on their own use of Arabic were also identified in order to establish the extent to which their views coincided with that of their students. This study adopted a qualitative approach and data were gathered through classroom observations, semi- structured interviews (in form of stimulated recall interviews), and open-ended questionnaires. Classroom observations were used to identify the extent, as well as the functions, of teachers’ L1 use and to examine whether the degree of teachers’ Arabic use varied according to their students’ level of proficiency. In addition, stimulated recall interviews were employed to explore students’ cognitive and affective responses to their teachers’ L1 and L2 use and students’ preferences for their teachers’ L1 background. The open-ended questionnaires were used to understand whether teachers’ and students’ views on the use of L1 by teachers coincided. The findings suggest that the way that Arabic is used by teachers in the Saudi EFL classroom varies according to the teachers’ L1 background in terms of the consistency, frequency, and the functions of the Arabic used by those teachers. Regarding students’ preferences for their EFL teachers, more than one third of the students (37%), the largest group regarding this aspect, preferred to be taught by a competent English teacher irrespective of their nationality or background; this clearly indicates that some students put emphasis on the pedagogy and professional skills of teachers rather than on their native status. The findings also suggest that a number of common cognitive responses are employed by students, mainly comparing English and Arabic grammatical rules, memorising new words, and making connections between Arabic and English. Furthermore, the results indicate that for most students (21 out of 30) Arabic helped to keep the affective filter low, making them feel more comfortable, happy and less anxious, whereas Arabic made the other students uncomfortable and more anxious. Moreover, it was found that the most frequently used strategies when students responded to teachers’ English use were mental translation, use of dictionaries and requesting clarification, while the least frequently used strategies were finding alternative English synonyms or avoidance. Finally, the findings indicate that teachers’ views generally coincide with students’ views about teachers’ use of Arabic. The findings from this study may benefit language teachers and programme designers to help them develop training programmes for teachers that take into account learner preferences regarding the background of their EFL teachers, particularly in the field of teaching EFL in the Saudi context. More importantly, the study suggests that learners should be trained how to use L1 as a successful learning strategy and that teachers should raise students’ awareness, especially those students with low proficiency in English, that Arabic can be used as a cognitive strategy, for example, to compare the similarities and differences between L1 and L2.

Speaker verification is the biometric task of authenticating a claimed identity by means of analyzing a spoken sample of the claimant's voice. The present thesis deals with various topics related to automatic speaker verification (ASV) in the context of its commercial applications, characterized by co-operative users, user-friendly interfaces, and requirements for small amounts of enrollment and test data. A text-dependent system based on hidden Markov models (HMM) was developed and used to conduct experiments, including a comparison between visual and aural strategies for prompting claimants for randomized digit strings. It was found that aural prompts lead to more errors in spoken responses and that visually prompted utterances performed marginally better in ASV, given that enrollment data were visually prompted. High-resolution flooring techniques were proposed for variance estimation in the HMMs, but results showed no improvement over the standard method of using target-independent variances copied from a background model. These experiments were performed on Gandalf, a Swedish speaker verification telephone corpus with 86 client speakers. A complete on-site application (PER), a physical access control system securing a gate in a reverberant stairway, was implemented based on a combination of the HMM and a Gaussian mixture model based system. Users were authenticated by saying their proper name and a visually prompted, random sequence of digits after having enrolled by speaking ten utterances of the same type. An evaluation was conducted with 54 out of 56 clients who succeeded to enroll. Semi-dedicated impostor attempts were also collected. An equal error rate (EER) of 2.4% was found for this system based on a single attempt per session and after retraining the system on PER-specific development data. On parallel telephone data collected using a telephone version of PER, 3.5% EER was found with landline and around 5% with mobile telephones. Impostor attempts in this case were same-handset attempts. Results also indicate that the distribution of false reject and false accept rates over target speakers are well described by beta distributions. A state-of-the-art commercial system was also tested on PER data with similar performance as the baseline research system. / QC 20100910