Calibration of Consonant Perception in Room Reverberation K. Ueno (Institute of Industrial Science,...
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Transcript of Calibration of Consonant Perception in Room Reverberation K. Ueno (Institute of Industrial Science,...
Calibration of Consonant Perception in Room Reverberation
K. Ueno (Institute of Industrial Science, Univ. of Tokyo)
N. Kopčo and B. G. Shinn-Cunningham (Hearing Research Center, Boston Univ.)
Introduction
Our auditory process is usually assumed to be static and fixed, dependent only on the input signals rather than on the state of the listener.
We naturally and fluidly compensate for
many interfering effects in everyday environments.
How do listeners calibrate auditory perception to acoustic interference?
Outline of the Study
PURPOSE: To explore how listeners calibrate auditory perception to room reverberation.
STRATEGY: Measure the effect of sudden changes of reverberation on speech perception.
Carrier phrase (RevC) Target (RevT)
Target (RevT)Carrier phrase (RevC) --- Lower performance
Un-matching reverberation
--- Higher performance
Matching reverberation
HYPOTHESIS: Consonants identification performance should be better when listeners have consistent room experience just prior to a test sound.
Stimuli
VC1 VC2 - - - - VC
* Rev-C ----- *Rev-T
Carrier phraseCarrier phrase TargetTarget
Speech source: VC (Vowel-Consonant) syllables with 16 consonants preceded by ‘o’ (/a/) ok, ot, op, of, od, og, ob, ov, oth(v), om, on, ong, oz, oth(uv), os, osh Two male and One female Recordings from corpus and a past study
Binaural room IR (BRIR): R1, R2, Anechoic
Test sound: VC*BRIR
Binaural room impulse responses R1: at relatively closer point
(12m) to the sound source in very reverberant church.
… reverberant
R2: at second balcony in a large concert hall (33m) … reverberant
Pseudo-anechoic BRIR are processed from R1 BRIR by a 5-ms time window. … dry (clear)
R1,Lch
R2,Lch
R1R2
Binaural room impulse responses R1: at relatively closer point
(12m) to the sound source in very reverberant church.
… reverberant
R2: at second balcony in a large concert hall (33m) … reverberant
Pseudo-anechoic BRIR are processed from R1 BRIR by a 5-ms time window. … dry (clear)
R1,Lch
R2,Lch
Processed for Pseudo-Anechoic HRTF
Experimental Design and Procedure
Test signals were presented with insert headphones. Subject’s responses for the final VCs were obtained by GUI using
16 graphical buttons labeled with the VCs. Number of VCs (2 or 4) in the carrier was fixed throughout blocks
of trials. Stimuli set (10 VCs x 3 talkers x 3 conditions = 90 trials in total)
were randomly presented in each block, repeated twice for each subject.
Subjects: 14 Native English speakers Percent-correct target identification scores were calculated for
each condition and subject.
tt =0.8 s
2 VCs carrier ----4 VCs carrier ----
VC1 VC2 VCVC1 VC2 VC3 VC4 VC
Rev-C ----- Rev-T
Carrier phraseCarrier phrase TargetTarget
t t t tRev-T
R1 R2 AE
Rev-C2VCs or 4VCs
AE RAE RAE -R1 Rm Rnm -R2 Rnm Rm -
Experimental Results
Carrier Reverberation
2VCs
% C
orre
ct ta
rget
iden
tific
atio
nRev-T
R1 R2 AE
Rev-C2VCs or 4VCs
AE RAE RAE -R1 Rm Rnm -A2 Rnm Rm -
4VCs
RmRm RnmRnm RAERAE
****
***
○: Rev-T = R1 ,●: Rev-T=R2
The effect of Rev-C is significant only with Rev-T=R2 (p<.0001): performance with matching reverberation is significantly higher than unmatching rev. with Rev-T=R2.
The effect of the carrier length is not significant.
Condition means of the PC: across 14 subjects and two repetitions
Error bars: showing 95 % confidence intervals for mean within subject (14 data)
Analysis of BNIR - reverberation
Frequency [Hz]Reverberation Energy
(Rev(50ms-)/Dir(0-50ms))
Frequency [Hz]
Reverberation Time (T60)
R1 R2
Frequency [Hz] Frequency [Hz]
FFT of early 100ms
Relative level [dB]
SNR and STI
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=125 Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=250 Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=500 Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=1k Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=2k Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=4k Hz
MT
F
1.0 2.0 4.0 8.00
0.2
0.4
0.6
0.8
1Fc=8k Hz
Modulation frequency [Hz]
MT
F
125 250 500 1k 2k 4k 8k-5
0
5
10
15
Frequency (Fc) [Hz]
SN
R [
dB]
AE (STI=0.99)R1 (STI=0.45)R2 (STI=0.45)
R1 R2
Summary
Calibration to room reverberation improved consonant perception in one (but not in the other) room explored in this study.
The two rooms differ in several acoustic characteristics, which might be the cause of this effect.
The calibration occurs quickly, after just a few words.
Thank you for your attention!