Enabling Use of AKG K1000 for Virtual Auditory Display

8/30/13
Individualized
Earspeaker Response Correction
The DESC9090 2013 Goal:
(Enabling Use of AKG K1000 for
Make the AKG K1000 Earspeaker
Virtual Auditory Display)
Disappear by Inverting
Individually-measured
Earspeaker Transfer Functions
W. L. Martens
21/08/2013
Frontward vs. Rearward Responses?
My Frontward vs. Rearward Responses?
It is generally assumed that the best Virtual Auditory Display
(VAD) performance will be achieved if the listener’s
individualized HRTFs (Head-Related Transfer Functions) are
accurately reproduced.
Virtual
Front
HRTFs were collected
for a frontward source
Virtual
Rear
and
for a rearward source
Human
Listener:
My Frontward vs. Rearward Differences?
4kHz
Front?
Earspeaker Response Correction?
It is generally assumed that the best Virtual Auditory Display
(VAD) performance will be achieved if the earspeaker system
used for playback is corrected using individualized ETFs
(Earspeaker Transfer Functions) for the listener.
Virtual
Front
1kHz
Rear?
Earspeaker responses should
be corrected at the ear…
Headphone
Listener:
Virtual
Rear
…for either frontward or
rearward sources
1
8/30/13
To begin: AKG K1000 ETF Measurements
K1000 Blocked-Meatus Measurements
As part of our 2013 lab exercise, we made blocked-meatus ETF
measurements of the AKG K1000 earspeaker system with the
intention of creating individualized ECFs (Earspeaker Correction
Filters) for equalizing HRTF-based synthesis for the HATS.
Virtual
Front
Dummy
Non-listener:
Headphones
For HATS!
Virtual
Rear
24-pole LPC Fit to K1000 ETFs
Mean 24-pole LPC Fit to K1000 Earspeakers
ETFs and ECFs for the K1000 Earspeakers
24-zero ECF for K1000 Earspeakers
2
8/30/13
How does the LPC Fit Work?
How does the LPC Inversion Work?
So again: AKG K1000 ETF Measurements
In preparation for our 2013 lab exercise, Luis made blockedmeatus ETF measurements for subject WLM when repeatedly
placing and removing the AKG K1000 earspeaker system
(so we can generate individualized ECFs (Earspeaker
Correction Filters) for me!
Virtual
Front
Headphone
listener:
Headphones
Corrected
Virtual
Rear
3
8/30/13
K1000 Blocked-Meatus Measurements
24-pole LPC Fit to K1000 ETFs
Mean 24-pole LPC Fit to K1000 Earspeakers
ETFs and ECFs for the K1000 Earspeakers
24-zero ECF for K1000 Earspeakers
HATS HRTF Measurements
Also in preparation for our 2013 lab exercise, we made blockedmeatus HRTF measurements of the HATS (Head and Torso
Simulator):
Virtual
Front
Dummy
Non-listener:
HRTFs
For HATS!
Virtual
Rear
4
8/30/13
HRTFs for HATS
HATS also has some Front/Rear Differences
(Head-Related Transfer Functions)
HATS also has some ILDs
(Interaural Level Differences)
5