The boom microphone has been used to record dialogue on a film set for decades. As a boom operator it can be difficult in certain situations to acquire an ideal placement for the boom microphone. It depends on the frame and the lighting on the set. There are situations where the boom operator is forced to place the microphone underneath the actors instead of the standard overhead position. To investigate the difference between these techniques, and what audio quality attributes that affect the viewers’ choice of preference, a listening test has been constructed. The subjects were instructed to choose preferences in four trials of stimuli that had been recorded with both microphone techniques. To collect further data the subjects were also instructed to describe the differences they perceived between the stimuli. A statistically significant result was not found, except for one of the trials, the trained listeners preferred the underneath microphone technique for the second female stimuli. A difference between the techniques was difficult to determine from the answers given by the subjects. The conclusion was made that there is not a clear preference between the microphone techniques. Even though one of the trials was significant a clear difference could not be found in the analysis of the qualitative data.

<div>The current technologies employed for autonomous driving provide tremendous performance and results, but the technology itself is far from mature and relatively expensive. Some of the most commonly used components for autonomous driving include LiDAR, cameras, radar, and ultrasonic sensors. Sensors like such are usually high-priced and often require a tremendous amount of computational power in order to process the gathered data. Many car manufacturers consider cameras to be a low-cost alternative to some other costly sensors, but camera based sensors alone are prone to fatal perception errors. In many cases, adverse weather and night-time conditions hinder the performance of some vision based sensors. In order for a sensor to be a reliable source of data, the difference between actual data values and measured or perceived values should be as low as possible. Lowering the number of sensors used provides more economic freedom to invest in the reliability of the components used. This thesis provides an alternative approach to the current autonomous driving methodologies by utilizing acoustic signatures of moving objects. This approach makes use of a microphone array to collect and process acoustic signatures captured for simultaneous localization and mapping (SLAM). Rather than using numerous sensors to gather information about the surroundings that are beyond the reach of the user, this method investigates the benefits of considering the sound waves of different objects around the host vehicle for SLAM. The components used in this model are cost-efficient and generate data that is easy to process without requiring high processing power. The results prove that there are benefits in pursuing this approach in terms of cost efficiency and low computational power. The functionality of the model is demonstrated using MATLAB for data collection and testing.</div>

Background. As long as Facebook has existed, advertisements have been present in the application in one way or another. The ads have evolved and become more sophisticated over the years. Today, Facebook creates groups with members having specific attributes and advertisers requests groups for whom Facebook shows the advertisement. Besides this, Facebook receives information from other sources such as browser cookies and ad pixels. All information that Facebook receive or collect is used in their algorithms to target relevant advertisement for each user. Objectives. To examine the possibility of Facebook eavesdropping through the microphone for marketing purposes and identify eventual keywords mapped between a spoken conversation and advertisement. Methods. Five controlled experiments were performed with two test phones and two control phones. These were treated equally beside the test phones being exposed to spoken conversations containing randomly chosen products, companies and brands. The content of the phones was compared to see whether advertisement was adapted to the spoken conversation in the test phones but not in the control phones. Results. No sponsored advertisements were present on the Facebook and Instagram application. Messenger contained ads indicating that Facebook might analyse the content of private messages to adapt advertisement. After adding the Wish application to the research, the results were still the same. Other contents in the Facebook news feed were analysed, however, the content analysed did not contain any evidence that Facebook eavesdrops on spoken conversations for marketing purpose. Conclusions. The experiments conducted were not sufficient enough to trigger sponsored advertisement. Therefore, no indications were found that Facebook is eavesdropping through the microphone or not.

Indiana University-Purdue University Indianapolis (IUPUI) / The current technologies employed for autonomous driving provide tremendous performance and results, but the technology itself is far from mature and relatively expensive. Some of the most commonly used components for autonomous driving include LiDAR, cameras, radar, and ultrasonic sensors. Sensors like such are usually high-priced and often require a tremendous amount of computational power in order to process the gathered data. Many car manufacturers consider cameras to be a low-cost alternative to some other costly sensors, but camera based sensors alone are prone to fatal perception errors. In many cases, adverse weather and night-time conditions hinder the performance of some vision based sensors. In order for a sensor to be a reliable source of data, the difference between actual data values and measured or perceived values should be as low as possible. Lowering the number of sensors used provides more economic freedom to invest in the reliability of the components used. This thesis provides an alternative approach to the current autonomous driving methodologies by utilizing acoustic signatures of moving objects. This approach makes use of a microphone array to collect and process acoustic signatures captured for simultaneous localization and mapping (SLAM). Rather than using numerous sensors to gather information about the surroundings that are beyond the reach of the user, this method investigates the benefits of considering the sound waves of different objects around the host vehicle for SLAM. The components used in this model are cost-efficient and generate data that is easy to process without requiring high processing power. The results prove that there are benefits in pursuing this approach in terms of cost efficiency and low computational power. The functionality of the model is demonstrated using MATLAB for data collection and testing.

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.

Rockfall, which is the detachment of rocks from a mountain, is a major hazard in the mining industry. To help combat this issue, this thesis aims to develop a sensor platform that is able to detect both the potential risk for rockfall and if any rocks do hit the ground. The platform requires wireless communication in order to output relevant information and in order to be part of an IoT-network of sensors.The design of the platform used three different sensors, a geophone, an accelerometer and a microphone. The main focus of the design process was to keep the platform low power, enabling long operation times. The final design had data output from both the microphone and accelerometer, with the accelerometer able to pick up the impact from a falling barbell. Wireless transmission of data is possible for up to 7.5 meters using Bluetooth Low Energy. The low power design was met, with an average current consumption of 26 milliamperes during transmission using Bluetooth Low Energy. That gives a theoretical operation time of 27 days with the battery used. As the accelerometer can pick up a falling object and with a theoretical lifetime of 27 days for the platform, it can be argued that the goals, except for detecting potential risk for rockfall, were met. In order to properly function, however, the platform needs more development, but the most important conclusion of the work is that it seems possible to build this type of platform. Further research and development outside the scope of the thesis is connecting several platforms together.

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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.