MSc SS Thesis Presentation

Estimating the room impulse response

Gabriele Zacca

The response of a sound system in a room primarily varies with the room itself, the position of the loudspeakers and the listening position. The room boundaries cause reflections of the sound that can lead to undesired effects such as echoes, resonances or reverberation. Therefore the location of these large reflecting surfaces is important information for sound field estimation in a room.

This work focuses on exploiting the inherent information present in echoes measured by microphones, to infer the location of nearby reflecting surfaces. A built-in microphone array is used that is co-located with the loudspeaker. The loudspeaker probes the room by emitting a known signal. A signal model is proposed which provides a relationship between reflector locations and measured microphone signals.

The locations of reflections are estimated by fitting a sparse set of modeled reflections with measurements. We present two novelties with respect to prior art. First, the method is end-to-end where from raw microphone measurements it outputs an estimate of the location of reflectors. Where specifically for the compact uniform circular microphone array the symmetry is exploited to create an algorithm that is of reduced computational complexity. Secondly, the model is extended to include a loudspeaker model that is aware of the inherent directivity pattern of the loudspeaker.

The performance of the proposed localization method is compared in simulation to the existing state-of-the-art localization methods. Real world measurements are also used to validate the proposed loudspeaker model.

Overview of MSc SS Thesis Presentation