2.9.12
Safety when using live speech
Dosimeter
A dosimeter is built into Madsen A450. If you are using live speech, it will
be working in the background as a safety precaution. The system monitors
the sound level versus duration of exposure(1).
If the patient is exposed to excessive levels of noise during the session, the
system will interrupt the signal and display a warning.
The chart shows the relation between the sound level and the maximum
duration of the exposure.
SPL Peak Level
Max time
< 79.9
NA
80 - 82
16 h
82.1 - 85
8 h
85.1 - 88
4 h
88.1 - 91
2 h
91.1 - 94
1 h
94.1 - 97
30 min
97.1 - 100
15 min
100.1 - 103
7.5 min
103.1 - 106
3.75 min
106.1 - 109
1.875 min
109.1 - 112
56.25 sec
112.1 - 115
28.13 sec
115.1 - 118
14.06 sec
118.1 - 121
7.03 sec
121.1 - 124
3.52 sec
124.1-127
1.76 sec
(1)Noise Exposure: Explanation of OSHA and NIOSH Safe.Exposure Limits and the Importance of Noise Dosimetry by Patricia
A. Niquette, AuD, Etymotic Research Inc.
2.9.13
Terms and abbreviations used in Speech testing
SDT
Speech Detection Threshold
SRT
Speech Recognition Threshold
MCL
Most Comfortable Loudness Level
UCL
UnComfortable Loudness Level
50
Madsen A450
2 Navigating in the Otosuite Audiometry module
