v anglickém jazyce The subject of the presented work is (the usage of) electroacoustic transducers in physics teaching. Its first part contains an overview of study materials, physics textbooks and a selection of academic studies dealing with the aforementioned topic. The central part of the thesis consists of three experimental activities in which electroacoustic transducers are employed. These activities may be adopted for home or laboratory work of students or in hobby groups. The first activity aims at exploring the principle of operation of or- dinary headphones. The second activity contains instructions for making a simple phone. The third, most extensive activity, focuses on the measurement of electrical properties of various electroacoustic transducers. The results are further used for a more detailed discussion of their operating principles. In the final part of the thesis, the usage and verification of one of these proposed activities in practice are discussed.

Smart speakers, such as the Amazon Echo or Google Home, have become ubiquitous in our daily lives due to their convenience, which offers interactive actions through the use of simple voice commands. These devices allow users to issue a wide range of commands for a variety of services. Users can ask in natural language questions about the weather, stock market, online shopping orders, and other general information. These devices can also be used to control lights, and heating systems, and set timers and alarms in the smart home. However, as smart speaker systems become more prevalent, new security and privacy, usability, and context awareness concerns will need to be explored and addressed. In this dissertation, we carry out the effort to understand and mitigate privacy leaks from third-party applications, improve usability testing using interactability metrics, and improve context-awareness in a multi-occupant home using background sounds. We first study the privacy risks resulting from smart speaker apps developed by third-party developers. Having a device permanently on and always listening led to concerns over user privacy. In addition, the use of the third-party app on smart speaker platforms introduces arguably more serious privacy risks than using only the platform's built-in apps, due to the open nature of the app marketplaces. We explore how an adversary can efficiently create a valid smart speaker app to eavesdrop on users. We developed three different strategies for implementing a malicious app. To mitigate this threat, we propose a strategy for users to limit the success of this adversary. We designed a measurement app to look at the effect of various environmental factors in the home impacting what the third party can hear, and therefore provide users with a recommendation to place their smart speaker in locations that limit the success of this adversary. Next, we propose the idea of an interactability score to quantify how well a smart speaker app can accept potentially different ways a user may express their commands. However, voice-generated input data creates many unpredictable test cases since there are many different ways of how someone will express the same intention. In addition, each third-party developer could implement their own voice commands, making it difficult for users to remember what commands a particular app can process. The architecture of current smart speaker apps further complicates the testing process since the app is hosted on the smart speaker platform as a black-box. Therefore, we develop a testing framework to automatically and systematically evaluate the interactability of the smart speaker applications. It measures how well an app has been implemented to accept different kinds of user interaction. We also focus on improving context-awareness access control for smart speakers. The convenience of these devices is tempered by the possibility of performing unintended or intended actions. At home, the device is usually placed in a fixed location and accessed by multiple people with complex relationships between them, and these complex relationships can lead to complex access control requirements, where the context factors and interpersonal relationships should play a significant role. We design a system to be run on a smart speaker that makes use of the sounds in the home to estimate the current state of the house, e.g. number of occupants, activities being engaged, social relation of occupants, etc. This context information is used to decide whether to execute the command, prompt for confirmation or reject the command entirely. We also designed a simple pictorial configuration utility to help non-expert users configure their access rules. / Computer and Information Science

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Since storytelling is a growing form of teaching we wanted to interview teachers to see what their experiences and opinions were on the subject. Therefore the purpose of this study is to use interviews to examine teacher perceptions and experiences about storytelling and its effect on language development. I will investigate both the use when the teacher is telling a story but also when students are telling stories. With help from my supervisor I was able to come up with interview questions that would help me answer my research question. After the interviews I reviewed the answers and analyzed them. I chose to have thematic rubrics in our results section. This enabled me to compare the different answers and analyze them. When I compiled the interviews I noticed that many of the teachers had the same opinion when it came to storytelling and how it can be used in school. In this degree project I found it relevant to analyze one part before going on to the next, therefore my analysis is integrated in my results section.I have done four qualitative interviews with four different teachers in four different K-3 schools in two different municipalities on the subject of storytelling. The interviews concern their experiences with the subject and how they use it in their classrooms.I have found that teachers have a positive attitude towards storytelling since they experience that their students benefit from this in their language development and overall motivation in school.

This paper investigates foreign born teachers working as EFL educators and their attitudes towards teaching as well as their roles in teaching the English language. The purpose of this study is to examine what motivates EFL teachers to work abroad and to explore why they are highly valued in non-English speaking countries. Through qualitative interviews with four (4) Filipino teachers working overseas as EFL educators their strengths and weaknesses are explored. My investigation shows that the Filipino teachers’ primary role is to teach communication and literacy skills. In addition, the reasons why these four teachers have chosen to work abroad are higher salary rates and better working conditions. However, their lack of knowledge of the local language and culture are their weaknesses. Finally, findings show that the respondents’ positive attitude towards teaching English abroad shows the importance of English in globalization.

In a world that is becoming more cosmopolitan, pedagogical approaches, particularly those that focus on diversity of cultures, have become paramount. As a result, this study attempts to gain insight into what pedagogical approaches K-3 teachers in Sweden use during their English lessons, and whether these approaches are more native speaker or interculturally focused and why that is. Initially, this degree project presents an overview of previous research made on the Native Speaker norm approach and the Intercultural approach. The findings show that the Native Speaker norm approach is more commonly used than the Intercultural approach. However, as English is a language used worldwide, the teaching of it should include content relatable to non-native speakers as well. Nevertheless, the Intercultural approach is relatively new and teachers still need the training and the tools to implement it. This paper builds on the content from interviews of three K-3 teachers and one assisting principal in different parts of Sweden. The main conclusions of this study are that (I) the teachers predominantly use a Native Speaker norm approach due to tradition; (II) the teachers lack training and knowledge of how to implement an Intercultural approach and, consequently, they do not know how to use it; (III) the teaching materials provided by the schools have an impact on what approach the teachers use; (IV) the teachers’ English teaching leaves their pupils struggling in coming to terms with their own identity in a global context, as well as appreciating norms and English varieties other than that of Standard English.

Speech anxiety is an issue that persists and presents itself innumerably in schools, especially affecting students who learning English either as their second language or as a foreign language. Speaking anxiety may stem from different sources and affect each individual student differently. The research question that is key to this research is “How can teachers support students who are struggling with speech anxiety?”The research for this thesis has been done through the use a qualitative interview with two secondary school teachers in Lund. The interview was structured after a semi-structured style to allow for guided questions and openness of any unexpected questions and answers during the interview process.The results of this research is that that tackling speaking anxiety in the classroom is no easy feat, although, from the literature and interview content it has been made clear that for a teacher to be successful in supporting their students, being prepared for possible difficulties, composed for sudden changes to lesson plans, and ready to adapt assignments where speaking is involved in order to allow students to be most comfortable and given their utmost honest performance while speaking in front of others.

Speaker Identification (SI) approaches based on discriminative Vector Quantization (VQ) and data fusion techniques are presented in this dissertation. The SI approaches based on Discriminative VQ (DVQ) proposed in this dissertation are the DVQ for SI (DVQSI), the DVQSI with Unique speech feature vector space segmentation for each speaker pair (DVQSI-U), and the Adaptive DVQSI (ADVQSI) methods. The difference of the probability distributions of the speech feature vector sets from various speakers (or speaker groups) is called the interspeaker variation between speakers (or speaker groups). The interspeaker variation is the measure of template differences between speakers (or speaker groups). All DVQ based techniques presented in this contribution take advantage of the interspeaker variation, which are not exploited in the previous proposed techniques by others that employ traditional VQ for SI (VQSI). All DVQ based techniques have two modes, the training mode and the testing mode. In the training mode, the speech feature vector space is first divided into a number of subspaces based on the interspeaker variations. Then, a discriminative weight is calculated for each subspace of each speaker or speaker pair in the SI group based on the interspeaker variation. The subspaces with higher interspeaker variations play more important roles in SI than the ones with lower interspeaker variations by assigning larger discriminative weights. In the testing mode, discriminative weighted average VQ distortions instead of equally weighted average VQ distortions are used to make the SI decision. The DVQ based techniques lead to higher SI accuracies than VQSI. DVQSI and DVQSI-U techniques consider the interspeaker variation for each speaker pair in the SI group. In DVQSI, speech feature vector space segmentations for all the speaker pairs are exactly the same. However, each speaker pair of DVQSI-U is treated individually in the speech feature vector space segmentation. In both DVQSI and DVQSI-U, the discriminative weights for each speaker pair are calculated by trial and error. The SI accuracies of DVQSI-U are higher than those of DVQSI at the price of much higher computational burden. ADVQSI explores the interspeaker variation between each speaker and all speakers in the SI group. In contrast with DVQSI and DVQSI-U, in ADVQSI, the feature vector space segmentation is for each speaker instead of each speaker pair based on the interspeaker variation between each speaker and all the speakers in the SI group. Also, adaptive techniques are used in the discriminative weights computation for each speaker in ADVQSI. The SI accuracies employing ADVQSI and DVQSI-U are comparable. However, the computational complexity of ADVQSI is much less than that of DVQSI-U. Also, a novel algorithm to convert the raw distortion outputs of template-based SI classifiers into compatible probability measures is proposed in this dissertation. After this conversion, data fusion techniques at the measurement level can be applied to SI. In the proposed technique, stochastic models of the distortion outputs are estimated. Then, the posteriori probabilities of the unknown utterance belonging to each speaker are calculated. Compatible probability measures are assigned based on the posteriori probabilities. The proposed technique leads to better SI performance at the measurement level than existing approaches.

“Family language policy” (FLP) is the accepted term for the field of study of the explicit planning and practices concerning language within a family unit in a home. Previous research has shown that FLP aids in the bilingual acquisition of a child (DeCapua & Wintergerst 2009; Kayam & Hirsch 2014; King, Fogle, & Logan‐Terry 2008; Li 1999; Oh; Schwartz 2008). However, there has been little research providing answers to whether FLP has a direct influence on language maintenance in adulthood, especially whether they acquire and maintain a native or native-like accent in both languages. The purpose of this study is to determine if any and to what degree FLP influences the bilingual accent acquisition of Spanish/English heritage speakers in the United States. This is a qualitative case study performed through sociolinguistic interviews of three families containing now adult simultaneous bilinguals who learned Spanish and English throughout childhood. After obtaining information of each family’s FLP, each participant (n = 9) was asked to provide a speech sample in both English and Spanish (the heritage language). These samples were then rated by native speakers of English and Spanish respectively. Results suggest that the level of perceived foreign accent of the heritage language may be influenced by certain factors included in an individual FLP, as well as the speaker’s language confidence and individual differences including language aptitude.

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