1. Sound Localization and Binaural Hearing
CHAPTER 12
Sound Localization and
Binaural Hearing

2. Binaural Hearing: Some Terms
AZIMUTH-angle from straight ahead in horizontal plane.
Minimum Audible Amgle- jnd for azimuth. (smallest at 0 degrees, largest near 90 and 270 deg.)
Binaural

3. LOCALIZATION & LATERALIZATION
ability to determine location of a sound source in the sound field.
LATERALIZATION:
perceived position of sound within your head for stimulation under headphones.
Binaural

4. Sound Localization
Binaural

5. LOCALIZATION CUES:
INTERAURAL TIME DIFFERENCE works best at low freqs: up to 0.65 ms at 90 deg.
INTERAURAL INTENSITY DIFFERENCE works best at high freqs: where head shadow exists.
PRECEDENCE EFFECT people can tell which ear was stimulated first.
Binaural

6. Masking Level Difference (MLD)
Masker and Signal in Each Ear
Test Threshold twice:
once with identical signals in each ear
once with 180 degrees out of phase R to L
Binaural

7. Masking Level Difference (MLD) (cont’d)
Signal is easier to detect with the interaural phase difference
Shift in threshold is about 12 to 15 dB at low frequencies.
Reflects processing in the auditory brainstem)
Binaural