Maico MA 50 Operating Instructions Manual Download Page 6

 

Operating Instructions MA 50 

 
 

Geba_MA50_Fe_11a.doc 

 

 

 

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2 Description 

The MA 50 is an audiometer for pure tone audiometric tests. It can be used 
for ENT diagnostics in the office, and for mobile audiometry in clinics, homes 
and abroad. 
 
Tests  can  be  performed  using  the  TDH  39  headphones  (AC),  B  71  bone 
conduction  receiver  (BC)  or  optional  insert  phones.  Built-in  test  signals  are 
pure tone, pulse tone, warble tone and narrow band noise.  
 
The MA 50 audiometer delivers 11 air conduction (AC) test frequencies from 
125 Hz to 8 kHz, with levels from -10 dB

HL

 to 120 dB

HL

  
Bone conduction (BC) can be tested with 11 test frequencies from 125 Hz to 
8  kHz  with  levels  from  -10  dB

HL

  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 dB

HL

 to 120 dB

HL

 

with 11 test frequencies from 125 Hz to 8 kHz. 
 
The hearing level is controlled independently for the signal and the masking 
channel by two detented knobs on the left and right of the instrument which 
can be operated from the side or the top. The level steps are 5 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. 
 
The bright LED-display shows level and frequency for each channel. 
 
As a result of modern microprocessor technology, the MA 50 is easy to use 
and is extremely reliable.  
 
The  audiometer  is  designed  to  be  extremely  service  friendly.  Automatic  test 
programs  make  trouble  shooting  and  the  yearly  calibration  as  easy  as 
possible. 
 
PC-Interface: 
A serial RS 232C interface for data transfer to a connected computer is built 
in.    The  optional  MAICO-audiometry  module  for  NOAH  enables  the 
automatic data transfer of all test results of the MA 50, likes tone audiogram. 
For more information see chapter 7. 

Summary of Contents for MA 50

Page 1: ...Operating Instructions MAICO MA 50...

Page 2: ......

Page 3: ...display of the MA 50 8 4 Pure tone audiometry 9 4 1 Air Conduction AC Testing 9 4 2 Uncomfortable Hearing Level UCL Testing 10 4 3 Bone Conduction BC Testing 11 4 4 Masking of the opposite ear 11 4 4...

Page 4: ...nded literature 16 7 Computer interface 17 8 Care and maintenance of the instrument 18 9 Trouble shooting 19 10 Technical Data 20 11 Warranty Maintenance and After Sales Service 24 12 Safety Regulatio...

Page 5: ...d And because MA 50 functions are software controlled upgrading later to new extended measurement functions will be simple and inexpensive That means that you have invested in a device that will adjus...

Page 6: ...dBHL to 120 dBHL with 11 test frequencies from 125 Hz to 8 kHz The hearing level is controlled independently for the signal and the masking channel by two detented knobs on the left and right of the i...

Page 7: ...MATERIAL AND THE SHIPPING CONTAINER SO THE INSTRUMENT CAN BE PROPERLY PACKED IF IT NEEDS TO BE RETURNED FOR SERVICE OR CALIBRATION All accessories are already packaged in the compartment connected wit...

Page 8: ...phone out of the compartment and connect the power cable to power The MA 50 operates with voltages from 96 to 240 V AC 44 Hz to 440 Hz To avoid pinching the cables when closing the cover lay the cable...

Page 9: ...the left masking channel All these settings are also shown on the display see picture 5 The hearing level can be easily adjusted with the right knob and the masking level with the knob on the left sid...

Page 10: ...ic tracking see chapter 4 4 masking channel selector key selects the right or left test ear 3 3 2 The display of the MA 50 The bright LED Display of the MA 50 shows levels and frequency The display sh...

Page 11: ...cy is automatically set to 1 kHz In the following example we assume that the right is the better ear Set the receiver selector to AC Set the left level control knob to a value just below expected hear...

Page 12: ...and the pure tone will frequency modulate The warble tone can also be pulsed as described before For hygienic reasons it is important to clean the ear cushions of the headphone see chapter 8 4 2 Uncom...

Page 13: ...14 The other side of the headband is placed in front of the opposite ear Set the receiver selector to BC Perform the test the same way as for air conduction see 4 1 Enter the measurements for all fre...

Page 14: ...e the common masking rules See chapter 7 for recommend literature Masking is an important part of practical audiometry It is necessary to be familiar with this topic to avoid errors which would lead t...

Page 15: ...a tracking feature for easy masking Adjust for the test signal using the level control knob then with the masking level control knob adjust for the corresponding masking level Now press the TRACK butt...

Page 16: ...he signal and 10dBHL for masking 5 3 Frequency selection Use the frequency keys and to select the frequency The maximum and minimum frequency depends on the receiver you have selected 5 4 Warble tone...

Page 17: ...uous presentation and presentation by pressing the STIM bar When in continuous presentation mode the STIM bars and function as interrupters The light above the STIM MODE key is on if continuous presen...

Page 18: ...re University Park Press 1980 Auditory Disorders A Manual for Clinical Evaluation Jerger Susan and James Jerger Boston College Hill Press 1981 Handbook of Clinical Audiology Katz Jack Baltimore Willia...

Page 19: ...ine transferred to the PC and stored in the database In pure tone audiometry initially all measured data is transferred as hearing threshold data This is indicated by the dot left from the center of t...

Page 20: ...up liquid no alcohol or spirits should be used The ear cushions Z of the headphone can be detached for cleaning To remove the ear cushion Z pull it gently from the earphone To assemble the cleaned or...

Page 21: ...ss vial is broken please insert new fuses 1 A slow blow Diodes light up but test tone is absent Green STIM LED or does not light Press STIM bar or When the diode lights up and the tone is available th...

Page 22: ...HL 40 dBHL 125 Hz 8 kHz no output speech 10 dBHL 85 dBHL Insert earphone with optional EAR 3A 10 dBHL 120 dBHL 750 Hz 1 5 kHz 10 dBHL 115 dBHL 500 Hz 4 kHz 10 dBHL 110 dBHL 250 Hz 10 dBHL 105 dBHL 6 k...

Page 23: ...t GND power fuses 1 A slow blow serial PC interface 1 GND 2 RX 3 TX RS 232 C 5 GND 6 DTR patient response switch sleeve GND tip in RI 500 BC bone conduction receiver sleeve GND tip out ZA 4 UA 8 Veff...

Page 24: ...BS 9A dB re 20 Pa dB 125 45 45 3 250 25 5 25 5 5 500 11 5 11 5 7 750 7 5 8 1000 7 7 15 1500 6 5 6 5 2000 9 9 26 3000 10 10 4000 9 5 9 5 32 6000 15 5 15 5 8000 13 13 24 Calibration values BC Receiver R...

Page 25: ...6 1 with Coupler HA 2 dB re 20 Pa dB 125 26 26 32 5 250 14 14 36 500 5 5 5 5 37 5 750 2 2 1000 0 0 36 5 1500 2 2 2000 3 3 33 3000 3 5 3 5 4000 5 5 5 5 39 5 6000 2 2 8000 0 0 42 5 Standard accessories...

Page 26: ...our instrument works properly the MA 50 should be checked and calibrated at least once a year This check has to be carried out by your dealer When returning the instrument for repairs it is essential...

Page 27: ...he audiometer works properly the instrument has to be checked and calibrated at least once a year The service and calibration must be performed by an authorized service center In accordance with the r...

Page 28: ...l Left Ear kHz 0 25 0 5 1 2 3 4 6 8 0 25 0 5 1 2 3 4 6 8 kHz LL 30dB HL 50dB HL 70dB HL KL 30dB HL 50dB HL When noise B G V or S is blocked inform the service center When the test tone is heard at the...

Page 29: ...50 Geba_MA50_Fe_11a doc 27 851 406 2 11 11 Specifications are subject to change MAICO Diagnostic GmbH Salzufer 13 14 1058 Berlin Telefon 49 3070 71 46 50 Telefax 49 30 70 71 46 99 e mail export maico...

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