RM500SL
®
User's Guide Version 3.4
June 2011
14 Occlusion Effect Test
Section overview
The occlusion effect refers to the unnatural sound of one’s own voice that results from
occluding the external ear. It is the result of the high SPL produced at the back of the
throat during a closed vowel utterance coupling to the closed ear canal via bone
conduction. Ear canal levels in a closed ear canal can exceed 90 dB SPL for closed vowels
such as “ee”. The effect is greatest below 1000 Hz. Clients with mild-moderate low
frequency hearing loss may describe their own voice as sounding “hollow” or as if they
were talking “in a barrel”.
The occlusion effect is measured by comparing the SPL in the ear canal to that outside the
external ear while the client vocalizes “ee” with the hearing aid in place and turned off.
Differences greater than 10 dB may result in complaints. This occlusion effect measurement
is useful in quantifying the extent to which venting or deep insertion is addressing the
underlying cause of the complaint.
Occlusion effect measurement
1. Refer to On-Ear Measures - Setup to prepare the system for use and for proper
positioning of the client and the probe tube.
2. Insert the earmold or custom hearing instrument into the ear, being careful not to
advance the probe tube further into the ear canal. A lubricant applied to the earmold or
custom instrument shell in the vicinity of the probe tube will make insertion easier and
prevent slit leaks around the tube.
3. Turn the hearing aid OFF.
4. Press <Tests>, then highlight and <PICK> [On-ear measures], then highlight and
<PICK> [Occlusion].
5. Highlight and <PICK> [Start test]. [Start test] changes to [Stop Test].
6. While the client vocalizes “ee” in a normal voice, highlight and <PICK> [Stop test] to
stop the test and freeze the screen. A red occlusion bar indicates an occlusion problem, a
yellow bar indicates a possible problem and a green bar indicates no problem.
7. Increase venting and repeat the test until a green bar is obtained.
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Summary of Contents for RM500SL
Page 1: ...RM500SL User s Guide Version 3 4 March 2010...
Page 9: ...RM500SL User s Guide Version 3 4 June 2011 EC Declaration of Conformity 9...
Page 10: ...RM500SL User s Guide Version 3 4 June 2011 10...
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Page 43: ...RM500SL User s Guide Version 3 4 June 2011 telecoil test 43...
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Page 78: ...RM500SL User s Guide Version 3 4 June 2011 Screen tour unaided screen 78...
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