How to perform Masking Level Difference (MLD) with Equinox Evo
Required equipment
- Equinox Evo
- A response button
- Headphones or insert phones
Test procedure
Go to Menu | Tests | MLD: Masking Level Difference.
Before mounting the headphones on the patient, explain to them that they will now hear tones (identical to the ones from the air conduction audiometry) and noise through the headphones. Emphasize that they should only focus on the tones and press the response button whenever a tone is audible.
Select the frequency that you would like to test; 250 or 500 Hz are good starting points.
Select S0N0 and set the intensity level for both channels at 60 dB.
Ensure that the decibel steps are set to 2 dB.
Make a masked threshold search. The threshold will typically be equal to the noise in the S0N0 condition.
When you have established a threshold, click Store on the Touch Keyboard or the PC keyboard.
SπN0: Select the SπN0 button, leaving the narrowband noise intensity level at 60 dB. The pulsed tone detection should lower significantly.
The difference between the S0N0 threshold and the SπN0 threshold will be the MLD.
S0Nπ: If desired, you can also establish the threshold for the S0Nπ condition.
Press Stop to end the test.
