Operation Manual MA 25/MA 25e
MA 27/MA 27e
8104818 Rev. 5
29
29/06/2021
Environmental
conditions
Operation:
+15 °C to +35 °C /
+ 59 °F to +95 °F
Relative humidity 30 % to 90 % (non-condensing)
Air pressure 98 kPa to 104 kPa
Maximum altitude: 2000 m / 6561 ft above sea level
Storage:
0 °C to + 50 °C / 32 °F to +122 °F
Humidity 10 to 95 % (non-condensing)
Transport:
-20 °C to + 50 °C / -4 °F to +122 °F
Humidity 10 % to 95 % (non-condensing)
Calibration
Calibration information and instructions are located in the
MA 25/MA 25e/MA 27/MA 27e Service Manual.
Air Conduction
DD45:
RadioEar Standard Values
DD65 v2:
RadioEar Standard Values
Transducers
–
Headband
tension
DD45:
Headband Static Force: 4.5 N ± 0.5 N
DD65 v2:
Headband Static Force: 10.0 N ± 0.7 N
Patient Response
switch
(MA 25e/MA 27e)
One push button
Patient
communication
MA 25e/MA 27e: Talk Forward (TF), built-in talk forward
microphone. 60-100 dB SPL, Continuously adjustable on
operation panel
Special tests/test
battery
MA 25e/MA 27e:
Automatic-recording audiometer according ISO 8253-1
Mode of Operation: Patient controlled modified Hughson-
Westlake procedure
Rate of Change of Sound Pressure Level:
•
Randomized with a maximum rate of dB step/5.6 s
depending on settings and patient response
Initial familiarization: 10 dB up and 20 dB down steps
•
Threshold determination (ascending method): 5 dB up and
10 dB down steps
Time window for patient response = On time (selection between
1 s or 2 s in device settings)
Inputs
Tone, Warble Tone +5%, 5 Hz (true sine wave frequency
modulation)
Accuracy
Frequency ± 2 %, Level ± 3 dB
Precision
Available Level Steps are 1 dB or 5 dB (chosen in Setup Menu)
Outputs
Left, Right
Stimuli
Warble Tone
5 Hz sine +/- 5 % modulation
Pulse Tone
Multiple pulses 250 ms or 500 ms; On/Off; pure tone or warble
tone
Presentation
Manual or reverse. Single, Pulse or Warble.
