摘要:人對噪音的感受除了音源本身的特性之外,尚需要考慮人耳之特性影響,本研究計畫旨在發展雙
耳量測技術並考慮心理聲學參數的聲音品質感測系統,量測結果可呈現人的聽覺感受,全程分兩個階
段分在兩年進行。
第一階段以開發雙耳技術為基礎,由仿人耳架構之雙麥克風系統擷取聲音量測訊號加上人因參數
的訊號處理,即發展「頭部關聯轉移函數表現人耳聽覺響應,並考慮心理聲學參數」的聲音品質感測
系統,有別於市售聲音感測系統。本計畫開發之系統較現有市售以單一麥克風量測聲音,輸出可呈現
響度之系統更接近人耳感受,但比市售「聲學仿真人偶系統」簡單很多。本計畫採用近似人頭及人耳
形狀之聲學特性的簡化模型,結合雙麥克風之感測系統進行聲音品質量測,經後端訊號處理系統計算
後,輸出各項心理聲學參數,如響度、銳度等參數值。本項研究已初步開發簡化雙耳雛形,經過無響
室實驗與聲學仿真人偶及單一麥克風量測結果比較。後續將持續研究,開發最佳的仿人頭與方人耳簡
化模型,與合適的心理聲聲學參數演算程序。此部分完成後可提供產業對聲音品質量測之基礎。
第二階段,將雙耳之感測技術應用於機具噪音源之辨識,藉由雙耳之特性,量測噪音之頻率與聲
壓,並進一步分析噪音源之響度、銳度等。在相同頻率相同聲壓下,結合雙耳技術與心理聲學,找出
不同產品設計狀態下之響度、銳度與厭煩程度。在降低噪音源惱人程度的考量下,改變機具結構特性,
以降低或消除不良噪音參數,使操作者不致因噪音的惱人造成情緒波動及其衍生之問題。
Abstract: For the evaluation of human reception on noise, besides the characteristics of noise source, the binaural effect should be taken into consideration. This project aims to develop a sound quality measurement system based on binaural technology with psychoacoustics parameter. The measured results can present the human reception of noise. This project is divided into two phases and will be carried out in two years.
In the first phase, the binaural technology will be developed. The acoustic signal will be measured through the dual microphones in a binaural architecture and the human factor will be considered, i. e. , the head related transfer function will be used as the response of human auditory including psycho-acoustic parameters. It is different from the current commercial sound quality measurement system. Compared with the commercial single microphone sound quality measurement with output of loudness, the developed system is closer to human binaural hearing; and it is much simpler than the product of “artificial head acoustics”. In this project we will develop a suitable simplified model of the human ears and head with characteristics similar to real human head and ears, in which the dual microphone will be embedded. When the system is applied to measure the sound, through the post signal processing system, various psychoacoustic parameters,
such as loudness or sharpness, will be obtained. The initial study of the project has been started in begin of this year, a simplified model of the human ears and head with two micro phones system has been designed, the measurement in the anechoic room was performed, the results have been compared with results of artificial head acoustic and single microphone. The suitable simplified artificial ears and head with the computing algorithm for psycho-acoustic parameters will be developed continuously in the project. The accomplishment of the binaural technology will provide a fundamental system of measurement of sound quality for domestic demand of various industries.
In the second phase, the binaural measurement technology will be applied to identification of sound
quality for machinery noise sources. Though the performance of the developed binaural technology, not only the frequency and sound pressure level of noise source will be measured, but also its loudness, sharpness, and annoyance can be obtained further. Combined the binaural measurement technology and the computing algorithm of psycho-acoustic parameter allows simultaneous of sound source to identify the loudness or the sharpness and annoyance of the different noise sources, even if they have the same distribution of pressure level versus frequency. Under the consideration of annoying level of the machine, its structural properties should be modified in order to reduce the negative psycho-acoustic parameters, the sound quality of the noise source can be improved, e.g. mitigation of sharpness level of machine, so that the effect of the annoying noise on the emotional stability of the machine operator will be reduced.