User guide
ELI
O
S
ECH001XN111-A4 – 07/2022
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Measurement on ECHOSOFT
6.6 Audiometry
6.6.5
Masking calculation help
The fourth tab of the audiometry window gives access to the patient's measurement history. A double click on the
date of the measurement will display it in the background (in transparency) to compare the current measurement with the
selected one.
In some cases, after a measurement without masking, the operator sees the need for a second test, by masking the
frequencies where there was potentially a transcranial transfer (ghost curves). An automatic masking calculation module
has been developed to help operators to calculate a suitable contralateral masking, for frequencies between 250 and 8000
Hz, from a previous test performed without masking.
When selecting a measurement in the "
Historic
" (1) which contains the air and bone tests, a table with suggestions
for the masking differential to use (3) is displayed. At the same time, the "
Auto Mode
" becomes available as a masking
control (2). It allows to automatically apply the masking differential suggested in the table (3) depending on the side
(right or left), the stimulus (air, bone or speech) and the frequency.
The masking in "
Auto Mode
" is calculated by applying the differential to the stimulation power sent. Thus, it varies
with each change in stimulation power, unless it reaches the limit set by the operator, or the limit of the stimulator output
power. Masking can be activated continuously (by selecting the "
continuous masking
" box) or at the same time as the
stimulation. In case where it is not necessary or if it cannot be calculated, the level is set to -30dB (no masking).
The masking for bone audiometry will only be calculated for the "history" frequencies tested by air conduction (AC)
and bone conduction (BC) in both ears. For AC audiometry the same rule is used, except for the frequencies 6 and 8 kHz.
For these frequencies, BC audiometry is not mandatory for the calculation of AC masking. Finally, for speech audiometry,
the AC and BC thresholds of both ears for at least one frequency (between 500Hz and 2 kHz) are required. The calculation
of the applied differential is performed as described in the section
Erreur ! Source du renvoi introuvable.
.
The automatic calculation system is only intended to make the operator's work easier; it is his responsibility
to check whether the calculation method (see
Erreur ! Source du renvoi introuvable.
) is suitable for the
specific case of each client.
