Seminar by Thomas Charpentier

Perception and objective measurement of the soundstage in a vehicle

With the tonal balance as well as the dynamic, the restitution of the sound stage in a car cabin is an important quality criterion for the audio feature. In this purpose, it is necessary to developpe a tool which measure and analyze the soundstage as it perceived by the listeners in a vehicle, in a binaural way. This PhD aims to define objective criterions based on signal processing metric of musical stereophonic signal. These criterions must, for example, describe the front stage localization of a music as well as the “immersion”, which is the non-localizable part of the signal (Reverb, Room effect etc…). This problem is complex as the characterization of spatialized “sound object” in a stereophonic record involves perception aspects (binaural perception) as well as cognitive aspects (the ability of individuals to separate and localize multiple sounds objects in space).

In order to find those convenient metrics, several aspects of the problem must be studied, such as sound source localization ability of the human brain, how does it behave when being feed by synthetic audio signal, such as recorded musical content, and what is the impact of the cabin from the car’s sound system to the listener’s head. The problem will be addressed with simple signal to begin, such as one sound object. Then, stereo music contents will be studied, that are made of much more complex scene. At the end, object based audio signals (commonly called “3D audio”, such as Dolby Atmos) might also be studied.