聽力檢查室背景音量測定評估

Survey of Background Noise Level in Audiometric Room

聽力檢查是一項用來量測因噪音所造成聽力傷害之有利工具，特別是對於從事噪音作業的勞工而言。然而，準確而成功的聽力檢查必須仰賴良好的檢查環境，特別是聽力檢查室背景音量的大小是影響聽力檢查品質最重要的因素之一。因此，本研究針對全國92 家勞工健康檢查指定醫療院所之聽力檢查室，進行背景音量測定及其頻譜分析，藉以了解現今國內醫療院所聽力檢查室的實際狀況，以提供醫院及主管機關作為聽力檢查品質標準及規劃聽力保護計畫之參考。本研究發現如下：針對92 家健檢指定醫療院所119 間聽力檢查室各分頻背景音量測量結果，發現各分頻背景音量最好與最差的差距平均值為65.3dB，顯示本研究中的聽力檢查室優劣差距甚大。再以各分頻個別檢視，發現各檢測醫院之分頻背景音量隨著頻率的降低而增高，顯示聽力檢查室較無法阻隔低頻的音量，此結果與國外的研究或文獻相當一致。將研究結果與美國OSHA 1983 標準值比較，發現有93.3%的聽力檢查室合於標準，若與較嚴格的美國ANSI 1991 標準做比較時，則各分頻完全符合標準的聽力檢查室只剩37.0%，統計發現，多數的不合格情形發生在500Hz 以下的低頻部分。此次本研究特別針對健檢巡迴車內聽力檢查室進行量測評估，結果發現其各分頻的背景音量值幾乎都高於其他醫院內聽力檢查室的平均音量值。若與美國OSHA 1983 或ANSI 1991 等標準比較時，均有半數以上的頻率超出標準，顯示健檢巡迴車可能無法取代一般醫院內的聽力檢查室進行聽力檢測的工作。由本研究的結果發現，國內現今聽力檢查室的設置與管理有著相當程度的差異，其原因可歸咎於國內迄今尚無聽力檢查室的設置規範與標準。因此，國內宜參考國外現有之標準，配合我國之需要，及早訂定出我國的聽力檢查室的設置規範及背景音量標準，以期提昇國內聽力檢查之品質，維護勞工健康之權利。

Audiometric testing is a suitable tool to detect hearing loss due to noise exposure, especially among workers in noisy operations. However, a dependable test depends on a good test environment, especially on background noise, which is one of the most important factors affecting quality of the audiometric test. Therefore, this study involved assessing volumes and frequency spectrums of background noise in audiometric rooms of 92 hospitals to understand current conditions of audiometric rooms in our country, and to offer a reference in quality standard of audiometric test and development of hearing conservation program. The result of background noise frequency spectrums for 119 audiometric rooms within 92 hospitals. Showed that for all spectra the difference mean in volume between the most quiet and the noisiest about 65.3 dB. It indicated that the quality of audiometric rooms varied widely. It was also found that background noise would increase as frequency decreased. It indicated that audiometric rooms could not block low frequency noise. Compared the result with 1983 OSHA standard, 93.3% of audiometric rooms met the requirement. However, compared with stricter 1991 ANSI standard, only 37.7% of audiometric rooms were qualified. Most of the disqualified had background noise exceeding the standard below 500 Hz. This study especially studied the effectiveness of audiometric rooms on mobile examination units. It was found that volume sat all spectra were higher than those in hospitals were. If we compared the results with 1983 OSHA standard or 1991 ANSI, more than half would exceed the standard. This indicated mobile units would not be able to replace testing in audiometric rooms in hospitals. From the results of the study, the audiometric rooms in our country varied significantly in terms of instrumentation and management. The authorities need to establish a protocol for establishing audiometric rooms, as well as volume standard for various spectra, in reference to existing international standards and national conditions, so that workers health will be protected with quality hearing tests.