Maico MA 53, Руководство по эксплуатации

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Operating Instructions MA 53
Geba_MA53_e_13a.doc 5 851 430/3 11/11
2 Description
The MA 53 is a two-channel audiometer for pure tone and speech
audiometric tests. It can be used for ENT diagnostics and hearing aid fittings
in the office, and for mobile audiometry in clinics, homes and abroad.
Tests can be performed using the DD45 headphones (AC), the optional high
frequency headphones HDA 200, B 71 bone conduction receiver (BC) or
optional insert phones and loudspeakers (FF). Built-in test signals are pure
tone, pulse tone, warble tone, narrow band and broadband noise. The MA 53
has stereophonic microphone inputs for live speech audiometry, an input for
an optional tape/CD player with speech test material and an additional input
for a second tape/CD player (i.e. for external masking signals).
The MA 53 audiometer with the standard DD 45 delivers 11 air conduction
(AC) test frequencies from 125 Hz to 8 kHz, with levels from -10 dBHL to 120
dBHL.
With the optional high frequency HDA 200 it delivers 17 air conduction (AC-
HF) test frequencies from 125 Hz to 16 kHz, with levels from -20 dBHL to 120
dBHL.
Bone conduction (BC) can be tested with 11 test frequencies from 125 Hz to
8 kHz with levels from -10 dBHL to 70 dB HL (with the standard bone
conductor B 71 the frequency range is limited from 250 Hz to 6 kHz).
The optional insert phones EAR 3A submit levels from -10 dBHL to 120 dBHL
with 11 test frequencies from 125 Hz to 8 kHz.
Optional loudspeakers are available for free sound field measurements (FF).
The new, portable loudspeakers MAICO SBC have a dynamic range from -10
dBHL to 80 dBHL at 1m distance, for nine test frequencies from 500 Hz to 8
kHz. The frequency range for speech is 500 Hz to 8 kHz with levels up to 80
dBSPL.
The Canton loudspeakers (not available in the USA), deliver levels up to 90
dBHL at 1m distance over the entire frequency range from 125 Hz to 8 kHz.
The MA 53 has also separate line level outputs for an external amplifier.
The hearing level is controlled independently for each channel by two
detented dials on the left and right of the instrument which can be operated
from the side or the top. The level steps are 5 dB and can be changed to 2 dB
or 1 dB. The signal STIM bar and the frequency up/down keys are just beside
the level control knobs for easy one handed control of level, frequency and
signal presentation.