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Appendix 1 ‒ Speech Audiometry
The Siemens SD 270 audiometer may be used in the following
speech modes of operation. However users should be aware that
there is a growing body of professional opinion that Live Voice
speech audiometry is generally not recommended. For recorded
speech audiometry, only material with a stated relationship with
the calibration signal should be used. Softkey 1 switches between
MIC1 (live) or LINE (recorded) inputs.
Headphone and Free Field Testing
Note that the line outputs from the instrument (used for free-field
testing) are only active when FREEFIELD is selected.
If headphone testing is being performed, it is recommended that
any attached amplifier should switched off
If Free Field testing is being performed, this option must always
be selected on the audiometer; this disconnects headphones,
bone vibrator and masking insert outputs, and ensures that the
correct calibrated output levels are achieved
Free field equivalent output is available from the headphones in
Speech mode (see Section 3.6 of this operating manual)
Operator Monitoring
Where an acoustic booth/room is used, a patient microphone is
connected to the MIC2 input, while the operator headset/earpiece
is connected to the MONITOR output. The operator listening levels
may be adjusted as follows:
The level of the speech signal is controlled by the +Hz and -Hz
keys, giving 2dB steps
The level of the patient‘s responses is controlled by using the
SIGNAL rotary control while pressing and holding TALKBACK