People are usually directed towards each other in conversations, to make it easier to hear what is being said. Algorithms for voice and speech recognition works in a similar way, regarding the microphone direction towards the sound source. In this thesis in electronics has therefore a servo control with binaural sound localization been implemented on a microcontroller connected to two microphones. When people perceive sound, the brain can estimate the sound source direction by comparing the time taken by the sound reaching one ear to the other [1]. The difference in time is called the interaural time difference, and can be calculated using various techniques. An exploratory comparison between the techniques cross-correlation and cross-spectrum analysis was carried out before implementation. Advantages and disadvantages of each technique were evaluated at the same time. The result is a functioning servo control, that uses a cross correlation algorithm to calculate the interaural time difference, and controls a servo motor towards the sound source with a P-regulated error reduction method. The project was implemented on the microcontroller ATmega328P from Atmel without using floating point calculations. The thesis was carried out on behalf of the company Jetspark Robotics.

This paper explores how vision affects spatial audio perception in virtual reality. We created four virtual environments with different reverb and room sizes, and recorded binaural clicks in each one. We conducted two experiments: one where participants judged the audio-visual match, and another where they pointed to the click direction. We found that vision influences spatial audio perception and that congruent audio-visual cues improve accuracy. We suggest some implications for virtual reality design and evaluation.

In this work is presented stochastic model of binaural hearing in context of another alternative models. According to latest experimental data on mammals, inhibition plays a role in interaural time difference recognition, which is a key for low frequency sound source localization. The outputs of experiments may lead to the conclusion that the binaural hearing works differently in mammals compared to birds. Nowadays there are a few theoretical works addressing this new phenomena, but all of them are relaying on a very precise inhibition timing, which was never proved as physiologically valid. On the other hand, models described in this work are based on the fact, that every neuron has a random delay when reacting to an excitation. If this time jitter is taken into account and combined with inhibitory signal, delay in the neuronal circuit and coincidence detection, then the output firing rate corresponds to the azimuth of the sound source. In this work it is shown, that such a neuronal circuits are giving the same output results compared to experimental data. The models are supported by analytical computations and numerical simulations including simulation of cochlear implant.

In this work is presented stochastic model of binaural hearing in context of another alternative models. According to latest experimental data on mammals, inhibition plays a role in interaural time difference recognition, which is a key for low frequency sound source localization. The outputs of experiments may lead to the conclusion that the binaural hearing works differently in mammals compared to birds. Nowadays there are a few theoretical works addressing this new phenomena, but all of them are relaying on a very precise inhibition timing, which was never proved as physiologically valid. On the other hand, models described in this work are based on the fact, that every neuron has a random delay when reacting to an excitation. If this time jitter is taken into account and combined with inhibitory signal, delay in the neuronal circuit and coincidence detection, then the output firing rate corresponds to the azimuth of the sound source. In this work it is shown, that such a neuronal circuits are giving the same output results compared to experimental data. The models are supported by analytical computations and numerical simulations including simulation of cochlear implant.