title: Correction method for averaging slowly time-variant room impulse response measurements.
abstract: Various methods exist for room acoustic measurements. To increase the signal-to-noise-ratio (SNR), averaging of repeated room impulse responses (RIR) can be performed under the assumption of time-invariant systems. Associated with a study of the Paris Notre Dame cathedral, time-variances due to minute temperature changes were observed which confounded results of averaged RIRs, producing significantly shorter reverberation times. A correction method for such time-variance of the acoustic system is proposed, based on time-stretching. Following correction, reverberation times of averaged RIRs were comparable to expected tolerance ranges for measurements, well within one just noticeable difference, while also exhibiting a mid-frequency SNR gain of 8 dB.
authors.affiliation: Audio Acoustics Group, Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur, CNRS, Rue John von Neumann, Campus Universitaire d'Orsay, 91405 Orsay, France postma@limsi.fr, brian.katz@limsi.fr.
authors.forename: Barteld N J
authors.initials: BN
authors.lastname: Postma
authors.affiliation: Audio Acoustics Group, Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur, CNRS, Rue John von Neumann, Campus Universitaire d'Orsay, 91405 Orsay, France postma@limsi.fr, brian.katz@limsi.fr.
authors.forename: Brian F G
authors.initials: BF
authors.lastname: Katz