A NEWLY DEVELOPED HEARING RISK DOSIMETER AND ITS APPLICATION TO THE HEARING DAMAGE RISK ASSESSMENT

Research Project

Project/Area Number	08670468
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Public health/Health science
Research Institution	THE INSTITUTION FOR SCIENCE OF LABOUR
Principal Investigator	ITO Akiyoshi THE INSTITUTE FOR SCIENCE OF LABOUR,RESEARCH DEPARTMENT,SENIOR RESEARCHER, 研究部, 主任研究員 (30151492)
Project Period (FY)	1996 – 1997
Project Status	Completed (Fiscal Year 1997)
Budget Amount *help	¥2,100,000 (Direct Cost: ¥2,100,000) Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	NOISE EXPOSURE / HEARING ACUITY / TEMPORARY THRESHOLD SHIFT / RISK ASSESSMENT / PERSONAL MONITORING / 騒音ばく露 / 個人モニタリング
Research Abstract	A operation unit for hearing risk dosimeter was newly developed to calculate rapidly the estimated noise induced temporary threshold shift (NITTS). This dosimeter is expected to contribute to the hearing damage risk assessment of personal noise exposure. The unit has six built-in filters that are A-weighted filter and five band-pass filters for the critical bands of NITTS for 2,3,4,6 and 8 kHz, and the DC voltage output of 0-1 V in proportion to a sound pressure level of each filter can be taken out. A dynamic range for input level is 50 dB and is changeable at 3 phases of 50-100, 60-110 and 70-120 dB, The size of the unit was small in 60 mm X 100 mm X 25 mm with weight of approximately 200 g. At the print workplace by a high speed rotary press, a worker wore both the new dosimeter and the personal noise dosimeter using a portable digital audio tape recorder (DAT) which had been already developed and in practical use. The results showed that the values of critical band levels for NITTS measure by the new dosimeter and estimated NITTS values well agreed with those of the former dosimeter. Therefore, this unit would be used practically for a personal noise dosimeter at work. It would also contribute to shorten the analysis time largely which had been as long as the recorded time in case of the former dosimeter using DAT.