Download El “TEN(HL) test” - University of Cambridge Hearing Group

Step-by-step instructions for measuring masked thresholds in the TEN(ER3)
The TEN(ER3) test for diagnosis of dead regions in the cochlea
1.
Brian C. J. Moore, Brian R. Glasberg and Michael A. Stone
This CD is intended for use in diagnosing regions in the cochlea where there
are no functioning inner hair cells and/or neurones; these are called dead regions.
The test is suitable for use with two-channel audiometers that employ Etymõtic
Research ER-3A earphones. The test involves measuring the threshold for
detecting a sinusoidal test tone presented in a special background noise called
“threshold-equalising noise” – TEN(ER3). The noise is spectrally shaped so that
the masked threshold, specified in dB HL, is approximately the same for all
frequencies in the range 500 Hz to 4000 Hz, for people with normal hearing and
for people with hearing loss without dead regions. The masked threshold is
approximately equal to the nominal level of the noise specified in dB HL/ERB N,
where ERBN stands for the equivalent rectangular bandwidth of the auditory filter.
For example, a level per ERBN of 60 dB HL leads to a masked threshold of about
60 dB HL. Absolute thresholds in dB HL can be determined either using the
audiometer or using the test tones on the CD. A reasonably high-quality CD player
is required for this. The level per ERB N of the noise to be used depends on the
severity of the hearing loss of the person being tested. If possible, the level per
ERBN should be about 10 dB higher than the audiometric threshold in dB HL in
the frequency region of interest. Levels up to 90 dB HL/ERB N can easily be
obtained with most audiometers, but levels above 85 dB may be judged as
unpleasantly loud by some hearing-impaired people.
Both absolute thresholds and masked thresholds can be measured using
standard audiometric methods. However a 2-dB final step size is recommended for
measuring masked thresholds in the TEN(ER3).
2.
3.
4.
5.
6.
7.
8.
Feed the left output from the CD player to the left (or A) line-level input on
the audiometer, and the right output from the CD player to the right (or B)
input.
Select the left (A) input for channel 1 on the audiometer, and the right (or B)
input for channel 2 on the audiometer.
Play track 1, set the audiometer so that both line inputs are played
continuously (press the interrupt buttons), and adjust both VU meters to read 0
dB. Turn off the two inputs (press the interrupt buttons).
Mix the two channels, and direct the mixed channels to the desired ear (left or
right).
Set the desired noise level using the channel 1 control. The level in dB HL/
ERBN corresponds to the dial reading on the audiometer.
Measure the masked threshold for each ear at each frequency, using tracks 2-8
of the CD, while playing the noise continuously (press the interrupt button for
channel 1). The test-tone level is controlled via channel 2. The level in dB HL
corresponds to the dial reading on the audiometer. Use a 2-dB final step size.
Repeat steps 4-6 for the other ear, if desired.
A dead region for a particular frequency is indicated by a masked threshold
that is at least 10 dB above the absolute threshold and 10 dB above the
TEN(ER3) level per ERBN.
If a dead region is detected at one or more frequencies, it is recommended that the
absolute threshold be re-measured for those frequencies, using the test tones on the
CD, and a 2-dB step size, to check that the masked threshold is 10 dB or more
above the absolute threshold.
 2012, Brian C. J. Moore, Department of Experimental Psychology, University
of Cambridge, Downing Street, Cambridge CB2 3EB.
The TEN(ER3) test for diagnosis of dead regions in the cochlea
The TEN(ER3) test
for diagnosis of dead regions in the cochlea
Brian C. J. Moore, Brian R. Glasberg and Michael A. Stone
Department of Experimental Psychology, University of Cambridge,
Downing Street, Cambridge CB2 3EB, UK
http://hearing.psychol.cam.ac.uk/
Track 1: Calibration tone on both channels: Use to set VU meters to 0 dB
Duration: 5 minutes
Track 2: 500-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 3: 750-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 4: 1000-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 5: 1500-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 6: 2000-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 7: 3000-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Track 8: 4000-Hz test tone on right channel, TEN(ER3) on left channel
Duration: 9.5 minutes
Brian C. J. Moore, Brian R. Glasberg and Michael A. Stone