Operating Instructions MA 42
Operating_Instructions_8100460-6_MA42_e_15a
18
8100460-6 1/15
5.1.4 Uncomfortable Loudness (UCL) Testing
Testing of UCL can be measured using pure tone or speech stimuli. The purpose
is to determine the dB level at which the stimuli become uncomfortable to the
patient. The UCL is described as the level between very loud and loud
perception of the test signal. This information is valuable for determining the
patient's upper dynamic range limit.
Warning! Because this test uses high sound pressure levels, it is
extremely important to perform this test using the utmost caution to
avoid damaging the ear. To prevent the possibility of extreme
discomfort by the patient, it is important to start the test with
comfortable levels.
Press the test mode selector key (13) underneath the display repeatedly until
UCL is highlighted and the LCD-display in the bottom row changes from HL to
UL. Start as described in chapter 5.1.1 with a test level of 60 dB
HL
. Present the
tone briefly (max. 1s). If the signal was recognized by the patient as “not
uncomfortable”, increase the level and proceed as described before. If the
signal was uncomfortable for the patient store the value. Proceed accordingly
with other test frequencies.
5.1.5 Most Comfortable Loudness (MCL)
Testing of MCL can be measured using pure-tone stimuli or speech. The
purpose is to determine the most comfortable listening level for the patient for
a given stimulus. The dB level at which the stimulus is the most comfortable is
determined. This level might be described as the level at which the patient
would be comfortable listening for an extended period of time. Press the test
mode selector key (13) underneath the display and select MCL in order to test
and store the Most Comfortable Loudness.
5.1.6 The SISI Test
The SISI (
S
hort
I
ncrement
S
ensitivity
I
ndex) is guided by the principle that
patients with cochlear impairment are hypersensitive to small intensity
increments. The continuous test tone is increased by 1 dB for a period of 0.2
seconds every 4.8 seconds. Whenever the increment is heard the patient has to
press the response switch. The MA 42 calculates the percentage of detected
increments. The SISI test information and the test score are shown on the LCD-
display. The test will end automatically after 20 presented increments. The score
is expressed as a percentage of ratio of the increments heard to the delivered
increments (all increments heard = 100% - no increments heard = 0%). A high
score indicates a cochlear impairment. A low score is related to normal hearing
or conductive or retrocochlear pathology.
Содержание MA 42
Страница 1: ...Operating Instructions MA 42 ...
Страница 2: ......