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- Sjödin, Fredrik, et al.
(author)
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Minimizing speech contribution using different microphone noise dosimeter positions
- 2012
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In: Proceedings of BNAM 2012. - Odense : University of Southern Denmark. - 9788799540006
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Conference paper (other academic/artistic)abstract
- Use of noise dosimeter recordings in low sound level environments is often problematic due to the voice contribution from the carrier. The aim of the study was to find a microphone position with low speech contribution while still providing an accurate sound level recording. An experiment with different microphone positions was conducted in a low sound reverberation room. Two types of noise dosimeters were used (Brüel & Kjaer 4445 and Larson Davis Spark 706-Atex). In repeated measurements the carrier was instructed to read a text chapter during 60 seconds and at a speech of level about 60 dB(A), acquired by practice, with different background noise and noise levels. White noise and preschool noise was used at sound levels 50, 60, 70 and 80 dB(A). The voice contribution to the background noise level was then measured. Three microphone positions were tested; on the shoulder, above the ear and on the back of the head. The position with the microphone placed behind the head of the carrier had the lowest speech contribution, less than 2 dB(A) to the background noise at 70 dB(A). This compared to positions right above the ear 6 dB(A and on the shoulder 12 dB(A).
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| 3. |
- Sjödin, Fredrik, et al.
(author)
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Tinnitus, noise and health effects in preschool environments
- 2012
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In: Proceedings of BNAM 2012. - Odense : University of Southern Denmark. - 9788799540006
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Conference paper (other academic/artistic)abstract
- The study included 93 employees at 17 preschools in the county of Umeå located in northern part ofSweden. Personal daily noise dosimeter recordings were made at five representative work days.Stationary noise recordings were made during the same days at two departments of each preschool, in theplaying halls and in the dining rooms. Besides audiometric tests, the employees rated their experiences ofthe noise, hearing and tinnitus as well as well as different health effects, on validated questionnaires.Tinnitus was reported among 31 per cent of the participants. The study group was dichotomized intoemployees with or without tinnitus. Employees with tinnitus reported higher prevalence of subjectivehearing loss, higher experiences of elevated sound levels at work, anxiety of the noise at work, chestpressure/pain, burn out symptoms, depression and reduced sleep quality. Significant differences wereseen for shoulder tension/pain. No group differences were seen for the objective personal or stationarynoise measures or the number of children present at the department. The results of the study are discussedin terms of underlying causes and the way in which the symptom interfere with experiences and healtheffects of the employees.
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