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D00073611 Siemens SD 270 Service Manual
c) The MASK rotary control changes the masking level in 5dB steps
d) If required, readjustment of the input signal level can be accessed by
temporarily deselecting the MASK key - then proceed as in 1.1d)
2.2
Procedure:
As described in 1.2 but adjusting the masking level as required.
3. Recorded Speech Audiometry to Headphones
3.1
Set Up:
a) Connect a CD, tape player, or other sound source to the LINE IN jack
socket; refer to Section 2.7 of this operating manual
b) Press SPEECH and use Softkey 1 to ensure that ‘LINE’ is displayed in
capitals (indicating that the line input is selected)
c) The line input is initially routed to the left earphone. To select the right
earphone press RIGHT
d) The input signal is adjusted in 1dB steps by use of the MASK rotary
control
e) Play the 1kHz calibration tone on the recorded material and adjust the
input signal such that the LEVEL dB bar graph reads 0dB; the
headphone output measured in an IEC 318 ear simulator will now be
89dBSPL for a setting of 70 dBHL
g) The output level is controlled in 5dB steps by the SIGNAL control
3.2
Procedure:
As described in 1.2 except that the operator plays the recorded material to
the subject.
4. Recorded Speech Audiometry to Headphones with Contralateral
Masking
4.1
Set Up - as described in 3.1 then:
a) Select MASK
b) Speech-weighted masking is now routed to the opposite earphone to
that selected
c) Select INT or EXT masking source using Softkey 4 (the option
selected is displayed in capitals); internal will be wideband noise and
external will be the competing noise from the signal source
d) The MASK rotary control changes the masking level in 5dB steps