Introduction
The MA25 from Maico
is School Health's smallest, most lightweight pure tone audiometer.
This ultra-portable pure tone screener is ideal for the professional
on the go, or school nurses that must screen at multiple locations.
Product
Overview and Description
The MA 25 Audiometer is an electrical audiometer that measures the
threshold of hearing for pure tone frequencies and loudness. It
is an air conduction audiometer where the sounds are transmitted
through earphones.
Ready to travel in
its own leather-look case, the MA25 weighs in at only 3.6 lb. Although small,
the MA25 is engineered to be tough and reliable. Enhancing its portability,
the MA25 can be powered by either a 9V battery, or the optional AC adapter.
User-friendly over-size knobs make adjusting frequency and hearing levels
simple. Easy push buttons allow the user to switch between right/left, pulse
tone and warble.
Although small and portable, the MA25 offers a full range of testing
opportunities. Frequency levels range from 250 Hz to 8000 Hz, and
signal intensities run from 10dB HL to 90dB HL.
Product
Use and Procedure
 |
Screening
instrument for use in identification audiometry programs. |
|
Used for
early identification of hearing impairment. |
 |
Routine
Uses: |
Air
Conduction Screening Testing
Screening tests are used to quickly identify those who may
have a hearing problem. For this purpose the hearing level
control is set to a fairly low setting but a level that most
people can hear. If the patient hears the test frequencies
presented in each ear, his/her hearing can be considered normal
or nearly normal. If the patient does not hear the frequencies,
he/she should be given a more thorough test. Remember, at
this point you are merely screening the hearing, not trying
to determine the lowest possible sound level they can hear.
The idea is just to determine if the basic test frequencies
at a fixed presentation level can be heard.
|
Procedure
Screening testing is typically done at four testing frequencies
in each ear. The usual frequencies tested are 500, 1000, 2000
and 4000 Hz. The fixed presentation level is usually in the
range of 20 to 30 dB HL, depending upon the test environment
and the purpose of the screening test.
Determining
what constitutes failure of a screening test is a matter of
professional judgment and should be decided upon before the
screening program begins. A common rule to follow is that
the screening test was failed if two or more frequencies in
both ears are not heard. Those not passing the screening test
may or may not have a significant hearing loss, but they should
be referred to have a more comprehensive audiometric test.
|
Air
Conduction Threshold Testing
A threshold test determines the softest sound a person can
hear at the test frequencies presented. Because the sound
is at the level where the person can barely hear it, the threshold
is usually defined as the lowest level at which the presence
of the tone can be correctly recognized during half of the
presentations at a specific level.
|
Procedure
Set the frequency selector switch to 1000Hz and the output
selector switch to the ear being tested first. Set the hearing
level control above the presumed threshold (such as 40 dB)
then present the tone. Decrease the level by 10 dB and present
the tone. If there is no response, raise the level by 10 dB,
and ascend in 5 dB steps. After two or three series at the
same test frequency, you should get a consistent level at
which the patient first responds during the ascending presentations,
and that is the threshold for that frequency.
|
Audiogram
Form
An audiogram is used to record the thresholds determined.
Each threshold measurement is marked on the audiogram before
making the next threshold determination.
|
Features and Benefits
|
Pulse tone,
warble operation. |
|
Fingertip
operation of Frequency and HL control. |
|
Push button
selector switches. |
|
Front controls
are easy to understand and simple to use. |
|
Exceptionally
lightweight, only 3.6 lbs. |
|
Battery
operated, optional AC adapter. |
|
Carrying
case included. |
Frequently
Asked Questions
| Q: |
Sometimes I have to leave the testing area for a sick child
and when I come back the unit does not work. Why does this
happen? |
| A: |
An automatic
power shut off occurs after 5 minutes of inactivity with the
audiometer to conserve battery life. To turn the audiometer
back on, the Power/Intensity switch must be turned to the
OFF position and then back to any desired intensity level.
|
| Q: |
How
often should the unit be calibrated? |
| A: |
An electronic calibration
check is recommended yearly to determine if a deviation from the standard
exists. The length of time that an audiometer should be operated before
recalibration varies depending on the treatment given to the unit.
School Health has an authorized service center for repairs and calibrations.
Click here to view information.
|
| Q: |
The
earphones do not seem to be working but I have a set from
another audiometer, can I use those? |
| A: |
The earphones
are an important and integral part of each audiometer. Earphones
cannot be exchanged between audiometers.
|
| Q: |
Sometimes,
especially when I test in a busy school, I do not get desired
results. How can I prevent this from occurring? |
| A: |
Excessive
sounds or noises in the chosen test site can produce a masking
effect and therefore affect test results. The selected site
should be away from conversations, hallway traffic and other
noise producing environments. The lower test frequencies are
most affected by these types of noise.
|
Technical
Specifications
| Frequency
Accuracy: |
+/-
2% maximum |
| Rise
/ Fall time: |
35
msec typical |
| Distortion:
|
.5%
typical, .3% minimum |
|
Crosstalk: |
- 100 dB minimum |
| On
/ Off Ratio: |
90 dB minimum |
| Frequency
Modulation: |
+/-
5% frequency modulating rate at 5 Hz |
| Voltage
Requirements: |
9 V alkaline battery (100 hours typical), optional AC |
| Dimensions: |
9.5" W X 3.7" H X 6.75" D
24cm W X 9cm H X 17cm D |
| Weight: |
3.6
lb / 1.6 kg |
| Frequency
Range: |
250
Hz to 8000 Hz |
| Hearing
Level Range: |
-10 dB HL to 90 dB HL |
Warranty
|
ONE
YEAR LIMITED WARRANTY: This warranty is extended
to the original purchaser of the instrument, by Maico, through
the Authorized Distributor from whom it was purchased. The
warranty covers defects in material and workmanship for a
period of one year from date of delivery of the instrument
to the original purchaser. Accessories, which are purchased
from Maico at the same time as the instrument, are warranted
for one year from the date of purchase. For additional information
contact your authorized Maico Distributor.
|
Reimbursement
The reimbursement code used with the MA-25 is #92551, Screening
Audiometry.
Product
Ordering Information
| SH
Catalog # |
Product
Name |
| 51024 |
Maico
(MA-25) Pure Tone Screener |
|
