otometrics MADSEN Midimate 622, Руководство пользователя

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7. SPEECH AUDIOMETRY
Either live voice or speech from tape or CD can be used for speech
audiometry and both measurements can be performed using the MIDIMATE
622. The audiometer has connections for microphone for live voice or tape
recorder (or CD player), from which you can play back word lists for threshold
and discrimination determination. The auxiliary tape channel (Tape 2) may
be used for recorded masking.
Note that only recorded speech materials with a stated relationship with a
calibration signal should be used.
7.1 SPEECH RECEPTION THRESHOLD
This threshold may be defined as the lowest SPL at which 50% or more of the
spondaic test words are repeated correctly. Spondees are words of two
syllables having equal stress, e.g. shotgun, airplane, workshop, etc. Spondees
Threshold word lists are used for this test. Each ear is tested separately and
the patient is requested to repeat the word he hears one at a time. Threshold
Word Lists
It is recommended to begin with the better ear, at 1000 Hz and with the
hearing level set at approximately 20 dB above the threshold at 1000 Hz. The
audiologist then begins to repeat the words reducing the intensity in 5 dB
steps until the patient is only able to repeat about half the words.
In order to obtain an exact result, a complete word list must be presented to
the patient (approximately 20 words). Under normal circumstances, it is
possible after the presentation of only a few words to find the threshold and
use the rest of the list is used for verifying the result. A descending, ascending
and then descending again technique has been recommended for both
recorded and live voice procedures (Norma T. Hopkinson).
This test may be performed using either live voice or recorded speech. In either
case, it is of utmost importance that the patient be adequately instructed.
7.2 DISCRIMINATION TESTING
For this test, use word lists with phonetically balanced words. Each ear is
tested separately and the patient is requested to repeat the words he hears.
Using the discrimination test you investigate the patient's ability to
discriminate speech at different intensities. In normal ears, the perception is
100% if the words are presented at a proper intensity. For certain types of
hearing loss, the patient only perceives about 40 to 50% of the presented
words, no matter what intensity is used.
MIDIMATE 622 OPERATION MANUAL 7. Speech Audiometry
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