環境騒音の長時間監視への携帯型音楽プレーヤの利用

抄録

In this paper, use of portable music players with recording function to measure the environmental noise for long hours is proposed, and the method of specific operation and measurement accuracy are discussed. Specifically, players are used to record the sound, and the recorded sound is analyzed on personal computer to calculate the noise evaluation function, such as A-weighted sound pressure level or equivalent continuous level. To check the accuracy, continuous recording for 24 hours at 20 sites, targeting at the sounds received in general residence, was carried out and equivalent continuous levels over a fixed period of ten minutes were calculated. As a result, difference to the measured value by the sound level meter turned out to be less than 0.5 dB (0.26 dB with rms) when built-in microphone of sound level meter was used to record (the AC output). For this reason, when used in combination with sound level meter, back-up usage with actual sound recording is expected. Also, difference to the measured value by the sound level meter was less than 2.0 dB (1.24 dB with rms), and it is considered fully usable when portable players are used alone for such as preliminary survey.