–
Int. CD
(Int. CD) (CD material in CD/DVD drive)
–
() (integrated Otosuite Speech Material or regular sound files)
–
Line In
(Line In) (analog input from external sound players, eg. CD, MD, MP3 or cassette recorders connected to
the audiometer via the
Line In
(Line In) input).
Important
•
If an external playback device is used to generate speech stimuli via the line input, care must be
taken to ensure that the player has a flat frequency response in the range 125 to 6300 Hz. The maximum allow-
able deviation from the average response level is +/-1 dB; the average response level should be measured over the
range 250 to 4000 Hz.
The headset microphone should be turned to a position just below the operator’s mouth.
If an external playback device is used to generate speech stimuli via the line input of Aurical Aud, only a high
quality CD player or similar device should be used; tape recordings may not provide a sufficient signal to noise
ratio. Preferably, the external device should deliver its output via a fixed-level line out connector. The input gain
on Aurical Aud should be adjusted to obtain a 0 dBVU reading when the calibration signal is played by the
external device.
8. You can find speech material files in the
File/track/list selection
(File/track/list selection) drop-down list.
Note
•
You should only use speech materials with a stated relationship between the level of the speech signal and
the calibration signal.
Speech materials delivered on CD or other media are normally accompanied by a description of this relationship.
You should follow the instructions supplied with the speech materials, using the VU-meter in Otosuite for adjust-
ment of input gain
If you are using built-in speech materials supplied with Otosuite, the speech levels have been adjusted according
to the original speech material instructions.
Note
•
Speech signals are calibrated in dB HL.
18
Aurical Aud
14 Performing speech audiometry
