Transcript Spatial Hearing

Binaural Hearing and
Human Sound Localization
Jens Blauert, Bochum
ακούειν (akúın)
to hear
Acoustics
Physics
Physics
Psychophysics
Psychophysics
“sounds”
“sounds”
“sensations”
“sensations”
acoustic event
auditory event
Head-Related Coordinate System
Some Key Words
Effect of Head Movement
Binaural Hearing and
Human Sound Localization
-
Introductory remarks
Directional hearing in the median sagittal plane
Directional hearing with sounds from lateral directions
Distance perception and inside-the-head locatedness
Summing localization
Auditory precedence and the echo threshold
The effect of interaural decorrelation
Binaural signal detection
Suppression of reverberance and coloration
Summary
Directional Hearing
Directional hearing in the median sagittal plane
in the Median Sagittal Plane
directional
bands
boosted
bands
1/3 oct
noise
Directional Hearing in the Median Plane
Directional Hearing with Sounds
from Lateral Directions
ear axis
Lateralization
attenuators
delay lines
Generation of ITDs and ILDs
Lateralization Blur for ILDs
Lateralization Due to ILDs
Lateralization Blur for ITDs
right ear
left ear
ITD-Lateralization Cues
Lateralization due to ITDs (broad-band signals)
Distance Perception
Inside-the-Head Locatedness
Summing Localization
Auditory Precedence
Echoes
Standard Stereo-Listening Arrangement
Summing Localization for Broad-Band Sounds
Ear Signals for Impulsive Sounds in Stereo
Summing Localization with Sideways Loudspeakers
after Plenge & Theile
primary auditory
event
broadband
sounds
echo
Auditory Effects with Two Coherent Sound Sources
Summing localization
Precedence Effect
Echo Threshold
signal: running speech of 50 syllables/s
delay of the reflection
Precedence Effect, Haas Effect and Backward Inhibition
The Effect of Interaural Decorrelation
Some Further Key Words
3 independent
noise generators
Controlling the Degree of Coherence
Spatial Extent of the Auditory Event
as a Function of Interaural Correlation
after Dubrovski & Cherniak, 1966
The Perceptive Phenomena of „Auditory Spaciousness“
Pioneer researches e.g.,
Kuhl, West, Marshall, Barron, Schroeder, Morimoto
Binaural Signal Detection
Suppression of Reverberance
and Coloration
The Binaural Intellegibility–Level Difference, BILD
Cherry’s Experiment
reverberant
chamber
threshold of perceptibility
degree of AM,
m
reverb
anechoic
Binaural Suppression of Reverberance
Danilenko’s Experiment
Advantages of Binaural Hearing
higher localization accuracy, lower blur
better source segregation (transparency)
suppression of undesired signals (cocktail-party effect)
suppression of coloration and reverberance (better articulation)
>> clearer auditory perspective<<
better sense of envelopment
higher auditory source width (auditory spaciousness)
>> better spatial impression<<
Higher Quality of the „Acoustics“!
Thank You for Your Attention
[email protected]
www.ruhr-uni-bochum.de/ika
More details regarding the topic of this lecture can be found in
Jens Blauert (1997)
Spatial Hearing:
The Psychophysics of Human Sound Localization
published by
The MIT Press, Harvard MA, ISBN 0-262-02413-6
TASK A
Young men and women (about 30 years old) have applied
to be admitted to a school for airline pilots.
For being accepted, they must have very good spatial-hearing
capabilities.
This is necessary, among other reasons, because they have to
respond correctly to signals from auditory displays in the cockpit.
Outline a battery of perceptual tests which could be used to
evaluate these capabilities.
(a) What would you measure?
(b) Which methods would you apply?
(c) What equipment would you need?
TASK B
The binaural-hearing capabilities of elderly people (over 65 years)
are to be evaluated by means of routine screening tests.
The goal is to assess their abilities to localize sounds in space and
to communicate under acoustically adverse conditions.
The information is needed , among other reasons, to decide if hearings aids
should be applied to them – and, if yes, which kind of these?
Outline a battery of perceptual tests that could be used to evaluate these
capabilities.
(a) What would you measure?
(b) Which methods would you apply?
(c) What equipment would you need?