Interacoustics Eclipse Additional Information page 50

Eclipse Additional Information Page 40
Rise/Fall and Plateau (applicable to Burst only)
Here you can design your stimulus manually (if you have selected "Manual" in the "Window" mentioned
above. Rise/Fall sets the number of sine waves it takes before the maximum intensity is reached. The same
number of sine waves will eventually be used in terminating the stimulation. Plateau is the number of sine
waves presented at full intensity. A Rise/Fall of 2 and a Plateau of 1 is popular for ABR testing (= total of 5
sine waves), and is the reference tone burst stimulus described in IEC 60645-3 (2007).
Intensity
Here you select the intensities (between -10dB and 100dB nHL or 20 and 135.5dB peSPL) you want tested
in the automated test sequence. The display of nHL or peSPL depends of your calibration settings.
If you want more than one test performed at the same intensity (for replication purposes) enter the desired
number of tests in the box below.
The intensities selected may be tested in Ascending or Descending order. The Soft Attenuator will assure
that all changes in intensity will happen gradually to allow for a more relaxing experience for the patient.
Also, when initiating a test, the stimulus will gradually increase intensity until the desired intensity is reached.
Testing of sleeping babies is facilitated by this feature.
If different intensities are needed, the user can enter in the box what intensity they want to see on the
screen. During recording, the user can manually select a new intensity from the user screen.
Stimulus Ear
Select the type of transducer you wish to use as stimulator for the recording.
The instrument is by default calibrated to insert phones (ABR insert or IP30) and optionally DD45s head-
phones and a B71 Bone conductor. The instrument is only calibrated to the type of transducers supplied with
your instrument.
Please note that all the factory default protocols use the insert headphone. Should you wish to use a differ-
ent transducer, select the new transducer under Stimulus Ear and save the protocol.
From the drop down "Msk" stands for masking, while "Mnt" in the VEMP protocols stands for monitor.
If Binaural Stim. is selected, the stimulus will be present in both ears. This procedure is used by some hos-
pitals in neonatal screening since evidence of hearing may be found quickly.
Note however that any response might originate for either ear and for individual examination of thresholds at
greater levels it is necessary to test each ear independently.
Masking offset and Masking stimulus
It is possible to apply masking during a measurement for both air conduction and bone conduction measure-
ments.
Masking is available with intensities at a pre-set number of dB above or below any selected test intensity. A
value of -40dB is normally appropriate for air conduction tests. The value should be increased to offset the
effects of an air-bone gap (conductive loss) in the ear to which the masking is applied. Masking is not availa-
ble if simultaneous stimulation is selected.
White noise (WN) is typically used as a masker for ABR stimuli, the WN level can be considered to be close
to effective masking level. The important exception from this rule of thumb is, that 500Hz TB and 500Hz NB