US 12,328,554 B2
Method for improving sound quality of sound reproductions or sound recordings in a room
Lasse Zinck Thomasberg, Viborg (DK); and Jakob Dyreby, Struer (DK)
Assigned to BANG & OLUFSEN A/S, Struer (DK)
Filed by BANG & OLUFSEN A/S, Struer (DK)
Filed on Sep. 28, 2022, as Appl. No. 17/936,255.
Claims priority of application No. PA 2021 00927 (DK), filed on Sep. 29, 2021.
Prior Publication US 2023/0096292 A1, Mar. 30, 2023
Int. Cl. H04R 29/00 (2006.01); G01N 29/12 (2006.01); H04S 7/00 (2006.01)
CPC H04R 29/001 (2013.01) [G01N 29/12 (2013.01); H04S 7/305 (2013.01); G01N 2291/014 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for improving a sound quality of a sound reproduction or recording in a room, the method comprising the steps of:
measuring an impulse response that comprises a linear response of the room;
performing a time domain analysis to determine resonances of the room;
for a group of room resonances selected based on predefined criteria determining a corresponding group of filters that, when inserted in a sound reproduction or recording chain in said room will counteract an unwanted effect of said group of room resonances on the sound quality of the sound reproduction or recording made in the room;
obtaining a measure of amplitude decay as a function of frequency of the measured impulse response by periodical cumulative decay spectrum (PCDS) analysis of the measured impulse response;
determining the room resonances by performing a peak detection analysis or a determination of local maxima on the measure of amplitude decay as a function of frequency;
choosing specific room resonances based on the predefined criteria, which room resonances are characterized by respective resonance frequencies Fi that are to be compensated for in order to improve said sound quality;
determining a bandwidth Qi and a gain Gi of each of said room resonances; and
based on the respective parameters Fi, Qi and Gi determining a compensating signal processing means comprising a filter bank or an equalizer that when inserted into the sound reproduction or recording chain substantially counteracts the unwanted effect of the chosen specific room resonances on the sound quality,
wherein there is defined a maximum number X of filters or pairs of filters to be used below FT and a maximum number Y of filters or pairs of filters to be used above FT.