D-0100778 Rev C
35
Stimulus Channel 1 and Channel 2
Tone
— The Tone pushbutton allows the selection of a pure tone stimulus for
air/bone conduction testing with the choice of five transducer types.
NOTE:
The selection of Tone on Channel 1 and Mic on Channel 2 is a valid
combination. This setting allows the operator to have contact with the patient,
especially a young child, without the need to select Talk Forward.
Mic
— The Mic pushbutton provides input capability from the test microphone
for monitored live-voice testing with the choice of five transducer types.
Int./Ext. A, Int./Ext. B
— Internal A and Internal B provide access to internal
.Wav files that may be used for recorded speech testing. External A and External
B accept recorded audiometric material from an optional digital music player or
compact disc player.
NOTE:
When using a digital music player, select the level using the
calibration track. First adjust the volume on the device until the VU meter
reads nearly 0 dB, then fine tune the intensity using the level selection.
Narrow Band Noise
— The NB Noise pushbutton selects a noise which is
geometrically centered at the selected test frequency and contains a 3 dB down
bandwidth of a 1/3 octave at a minimum and ½ octave at a maximum.
Speech Noise
— The Speech Noise pushbutton selects speech noise that is
calibrated in effective masking level and contains a spectrum of equal energy per
frequency from 100 to 1,000 Hz with a 12 dB/octave roll-off from 1,000 to 6,000
Hz.
White Noise
— The White pushbutton selects White Noise which is a broad
band signal containing acoustic energy at all frequencies between 125 Hz and
12,000 Hz. White noise is calibrated for pure tone effective masking if a tone
type signal is selected on the opposite channel and for speech effective masking
if a speech type signal is selected on the opposite channel.