User guide
ELI
O
S
ECH001XN111-A4 – 07/2022
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Measurement on ECHOSOFT
6.6 Audiometry
6.6.5.1
Color code
• Yellow (with the differential value indicated): frequencies that needs to be retested with contralateral masking.
• Blue : currently selected frequency.
In « Speech » audiometry, no frequency will be selected, the module will apply the appropriate masking for speech
audiometry
• Shaded: frequency not available in the reference test (in AC and/or BC).
• White (with « n/a »): frequencies that does not need to be retested.
• Red: missing information to compute the masking value (for example, the contralateral ear has not been tested)
6.6.5.2
« Automatic mode » audiometry with « Auto mode » masking
When using pure tone audiometry in "
Auto Mode
", with masking in "
Auto Mode
", only the frequencies shown in
the table with a yellow background will be tested (respecting the type of stimulation used - AC or BC). Make sure that
all the frequencies present in the reference test (from the "historic" tab) are activated in the configurations so that the test
with masking, if necessary, can be performed (See subsection
Erreur ! Source du renvoi introuvable.
).
6.6.5.3
Calculation method
Air conduction audiometry (AC):
If the difference between the AC threshold of the test ear and the BC threshold of the contralateral ear (CtL), at the
same frequency, is equal to or greater than the AC interaural attenuation (AI_AC), then masking is required. Different
types of stimulators may each have a specific AI_AC value (insert = 50dB; headset = 40dB). Therefore, the need for
masking and its value may vary depending on the stimulator used, which is automatically identified by the module.
In order to calculate the AC masking, the AC and BC thresholds of both ears at the frequency to be analyzed are
required (except for 6 and 8 kHz). If there are no BC thresholds at 6 and 8 kHz, the module calculates the average Rinne
(difference in thresholds between AC and BC) between 2 and 4 kHz and adds this value to the 6 kHz and/or 8 kHz AC
threshold to obtain the estimated BC threshold.
Efficiency criteria:
Differential = Rinne_CtL + 10dB − AI_AC
Maximum masking level:
Max differential = AI_AC − 5dB
Bone conduction audiometry (BC) :
If the BC threshold of the test ear is higher than in the contralateral ear (CtL), at the same frequency, or if the Rinne
of the test ear is greater than 10 dB, then masking is necessary.
In order to calculate the BC masking, the AC and BC thresholds of both ears at the frequency to be analyzed are
required.
Recommended value for the occlusion effect (OE)
Frequency (Hz)
250
500
1000
≥ 2000
EO
20
10
5
0
Efficiency criteria:
Differential = (the higher between ∶ Rinne_CtL and OE) + 15dB
Maximum masking level:
Max differential = 45 dB
Speech audiometry:
If the average AC threshold for conversational frequencies (between 500 and 2000 Hz) of the test ear minus 60 dB is
greater than one or more of the BC thresholds of the CtL ear, then masking is required.
In order to calculate masking for speech audiometry, the AC and BC thresholds of both ears for at least one frequency
(between 500 Hz and 2 kHz) are required. The results obtained at 250 Hz are not taken into account for the calculations.
