Acoustic Enhancement via Beamforming using Smartphones

The ubiquity of mobile telecommunication/computing (e.g. smartphones) is rapidly rendering new technological opportunities. Mobile devices are not only equipped with all kinds of sensors (i.e. microphones, loudspeakers, cameras, accelerometers, compass, etc.) but also with powerful processing units. Imagine you could have a crystalclear conference call without the need of expensive equipment in a special room, but by using the participant's smartphones to acquire, synchronize, process and send the acoustic signals without the need of a central computer.

In this project we are interested in acoustic enhancement via beamforming using smartphones. The acoustic signals in a conference call are prone to noise and echofeedback. Beamforming is a technique that exploits the spatial diversity of the many microphones in the smartphones to enhance the target signals. The microphones in the smartphones have, however, nonhomogeneous "directivity gains". This means the gain of the signals they acquire depends of the angle(s) of arrival. By considering the directivities in the beamforming process, a much better enhancement of the signals can be obtained. As discussed in the literature, some technical aspects to consider are: 1) How to better incorporate the directivity patterns depending on the geometry of the microphone array. 2) Assess the performance of the beamforming process in both anechoic and reverberated environments.

Assignment

• Implement and evaluate the performance of different state-of-the-art beamforming algorithms incorporating the directivity patterns found in commercially available smartphones.
• Conduct a research to asses the performance based on the geometry of the array and the impact of reverberation.
• Demonstrate the proficiency of the algorithms in a real scenario. If time permits it, a prototype demo is going to be built using smartphones, otherwise the demo will be implemented inMATLAB using a PC and a microphone array simulating the directivities of the smartphones.

Last modified: 2023-01-13