Appendix 1 - Speech Audiometry; Headphone And Free Field Testing; Operator Monitoring - Siemens SD 270 Operating Manual

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
ƒ
any attached amplifier should switched off
If Free Field testing is being performed, this option must always
ƒ
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
ƒ
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
ƒ
keys, giving 2dB steps
The level of the patient's responses is controlled by using the
ƒ
SIGNAL rotary control while pressing and holding TALKBACK
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