Cost-effective spatial decomposition method solution for impulse response capture and auralization
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Sound and vibration (MPSOV), MSc
Publicerad
2023
Författare
Simonsson, Victor
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Spatial decomposition method (SDM) is a method to parameterize a spatial room
impulse response into a scalar pressure value and a direction of arrival (DOA) for
each time sample. SDM can be therefore be used to simulate acoustics in enclosed
spaces and have proven effective when rendering to both headphones and loudspeaker
arrays. The aim of this thesis was to design and build a low-cost SDM
microphone array using MEMS microphones and investigate how different number
of microphones affect auralization performance. All impulse response capture, encoding
and decoding was implemented with Python, to be published as an open
source library. Python modules were implemented to support rendering as both
BRIRs and as virtual loudspeaker signals to be used in external auralization software.
Due to hardware limitations the SDM array was limited to 6 microphones,
although simulations were carried out to compare a 6 microphone array and
a 12 microphone array. These were shown not to have any significant perceptual differences
as expected from prior research. Listening tests were conducted where participants
compared binaural room impulse responses decoded from SDM with a reference
dummy head measurement. Two measurement situations were evaluated, clear line
of sight and occlusion between source and receiver. The listening tests showed that
neither measurement situation performed better than the other, relative to their
respective reference and anchor. No clear difference between the ratings of different
configurations of SDM encoding were found. All in all, this implementation proved
sufficient at encoding and decoding binaural SDM. With additional post processing
the audio quality will get even better
Beskrivning
Ämne/nyckelord
Acoustics, Audio Technology, Spatial Audio, Microphone Array, Binaural Audio