APPENDIX 1 - SPEECH AUDIOMETRY
28 MODEL 260 INSTRUCTION FOR USE
APPENDIX 1 - SPEECH AUDIOMETRY
The Model 260 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.
Use the SPEECH key to switches between MIC1 (live) or LINE (recorded) inputs.
Notes regarding the use of recorded test material:
• The audiometer line input is intended for connection to audio playback devices able to output signals having
the industry standard line level voltage amplitude of 0.707Vrms.
• Using other types of output (i.e. headphone sockets, laptop audio sockets) may result in a reduction of signal
level.
• While some compensation for a reduced level is possible using the audiometer, it is also possible to increase
the signal levels of recorded speech test material by using freely available P.C. software. Contact your
distributor for details.
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 be 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
• If free-field equivalent output is required from the headphones in Speech mode this option should be selected
(see Section 3.4.2)
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 FREQUENCY keys, giving 2dB steps
• The level of the patient's responses is controlled by using the SIGNAL keys while pressing and holding
TALKBACK; press the TALKBACK key to toggle talkback on and off
Test Modes in Speech Audiometry
Initially in speech mode either ear may be selected, with the output level controlled by the SIGNAL keys in 2.5dB or
5dB steps. Pressing TEST MENU routes the speech to both ears (Stenger test with speech), with the left output level
controlled by the SIGNAL keys and the right output level controlled by the MASKING keys. Pressing TEST MENU
again returns to the original speech mode.
A1.1 LIVE VOICE SPEECH AUDIOMETRY TO HEADPHONES
A1.1.1 Set Up:
a) Connect a microphone to the MIC1 input on the audiometer
b) Press SPEECH repeatedly to ensure that ‘MIC’ is displayed in capitals at the bottom left of the display (indicating
that the external microphone is selected)
c) The microphone is initially routed to the left earphone. To select the right earphone press RIGHT
d) The input signal level is adjusted in 1dB steps by use of the MASKING keys
To Next Page
Loading...
