
Page 30
D00073611 Siemens SD 270 Service Manual
c) The line input is now routed to the external amplifier and speaker; use
LEFT and RIGHT to select the required amplifier channel
d) Play the 1kHz calibration tone on the recorded material and follow the
calibration procedure in Appendix 2
e) The input signal is adjusted in 1dB steps by use of the MASK rotary
control
f) Adjust the input signal such that the LEVEL dB bar graph reads 0dB
6.2
Procedure:
As described in 3.2
7. Free Field Recorded Speech Audiometry with Competing Noise
(Audiometer-Generated)
7.1
Set Up: - as described in 6.1 then:
a) Select MASK
b) Select internal masking source using Softkey 4 (the INT option is
displayed in capitals); wideband noise is routed to the competing LINE
OUT channel
c) The level of competing noise is adjusted in 5db steps using the MASK
rotary control
7.2
Procedure:
As described in 3.2 but adjusting the competing noise level as required.
8. Free Field Recorded Speech Audiometry with Competing Noise
(Recorded)
8.1
Set Up: as described in 7.1 except:
a) Select external masking source using Softkey 4 (the EXT option is
displayed in capitals); competing noise from the signal source is
routed to the competing LINE OUT channel
b) Use the SIGNAL rotary control to adjust the signal channel and MASK
rotary control to adjust the noise channel
8.2
Procedure:
As described in 3.2 but adjusting the competing noise level as required.