Appendix 7 - Enabling Different Earphone Types - Siemens SD 270 Service Manual

Appendix 7 - Enabling Different Earphone Types

The audiometer is supplied calibrated with a primary earphone type.
Optionally, a secondary earphone type will have been enabled (and
calibrated) and this may be selected for use as described in Section 3.5.2
of this manual ("Select phones").
It is possible to specify an alternative primary earphone and also enable a
secondary earphone if this was not done at the time of shipment. Further
details of this procedure are described below.
However if these selections are changed it is the responsibility of the
operator or other technical staff to ensure that the appropriate
earphone(s) have been enabled, correctly calibrated and verified
before use.
1 Primary Earphone Type
The primary earphone type may be set to one of:
Interacoustics DD45
Telephonics TDH-49
Telephonics TDH-39
Eartone 5A (E-5A)
Note that the audiometer does not store calibration data for all of the
above earphone types. These are simply labels to aid the operator in
identification of the primary earphone type in use.
Note also that the option to output free-field equivalent levels in speech
mode is only available for the DD45 & TDH-39 earphones.
To set an alternative primary earphone type:
Enter calibration mode using the password as described in
Appendix 5 Section 1
Press the TALKBACK key to cycle around the selection of primary
earphone, secondary earphone and the main calibration display
SM010-3 Siemens SD 270 Operating & Service Manual
THEREFORE - IF AN ALTERNATIVE EARPHONE
TYPE IS SELECTED IT IS ESSENTIAL THAT THE
ACTUAL HEADPHONE TO BE USED WITH THE
AUDIOMETER IS THEN CALIBRATED WITH IT.
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