Interacoustics AT235 - Reference Values for Stimulus Calibration

Service Manual
AT235
V
6.2 Reference values for stimulus calibration
Freq.
Reference Equivalent Threshold Sound Level
(RETSPL)
[dB re. 20 µPa]
Variation of Ipsi
stimulus levels
for different
volumes of the
ear canal
Relative to the
calibration
performed on an
IEC 126 coupler
[dB]
Sound
attenuation
values for
TDH39/DD45
earphones using
MX41/AR or
PN51 cushion
[dB]
ISO 389
-1
(Interacoustics Standard)
ISO 389
-2
(Interacoustics Standard)
Interacoustics Standard
Interacoustics Standard
Interacoustics Standard
ISO 389
-4
(ISO 8798)
0.5 ml
1 ml
[Hz]
TDH39
EARtone
3A / IP30
DD65 v2
DD45
Probe
NB
Stimulus
Correction
Values
RETSPL
125
45
26
30,5
47.5
41
4
3
250
25.5
14
17
27
24.5
4
5
500
11.5
5.5
8
13
9.5
4
9.7
5.3
7
1000
7
0
4,5
6
6.5
6
9.7
5.3
15
1500
6.5
2
2,5
8
5
6
21 (1600 Hz)
2000
9
3
2,5
8
12
6
11.7
3.9
26
3000
10
3.5
2
8
11
6
-0.8
-0.5
31 (3150 Hz)
4000
9.5
5.5
9,5
9
3.5
5
-1.6
-0.8
32
6000
15.5
2
21
20.5
3
5
26 (6300 Hz)
8000
13
0
21
12
-5
5
24
WB
-8
-5
-8
-8
-5
7.5
3.2
LP
-6
-7
-6
-6
-7
8.0
3.6
HP
-10
-8
-10
-10
-8
3.9
1.4
*All figures in bold are Interacoustics Standard values.