2019年 7月 4日

純音性または衝撃騒音の客観的評価

純音性または衝撃騒音の客観的評価

音を美しいメロディーと認識するかまたは騒音と認識するかは、聞き手により受け取り方が違います。モーツァルトやバッハのファンは、アイアン・メイデン(ミュージシャン)コンサートのヘビーメタル音楽を騒音と感じるかもしれません。逆にダイハードロックのファンは、クラシックコンサートが退屈に感じるでしょう。車好きな人にはオートバイのグループの通過音は問題ないですが、地元住民にとってはうるさく感じられるはずです。つまり何が騒音で何が騒音にならないかは人により異なります。XL2サウンドレベルメータは、ISO 1996規格に準拠して騒音を客観的に評価します。

聞き手により音の感覚は異なりますが、騒音とうるささに関しては一般化された評価方法があり、議論の解決に役立ちます。それが評価騒音レベル Lrです。 この値はA特性時間平均サウンドレベル LAeq に、うるささが増す原因となりうる純音性や衝撃性に対する補正が加えられます。

Tonal and Impulsive noise is perceived as disturbing
An example of a tonal sound is the sound of a circular saw. Particular tones stand out from the spectrum. If these are significantly louder than the background noise, the noise may be perceived as annoying. Accordingly, a tonal penalty KT is applied for periods during which such a noise source is active. Also, impulsive noises, such as from a piledriver on a construction site, or a hydraulic press in a factory, can be perceived as particularly annoying and are therefore adjusted with the impulse penalty KI.


Gateway Noise Monitor Status
Data Explorer


First collect data, then create reports in peace
To determine the Rating Level Lr, the XL2 Sound Level Meter and the Data Explorer PC software are a perfectly-matched team. The XL2 stores all required level values as well as the 1/3rd-octave spectra in adjustable, short clock cycles. The XL2 also creates an audio file of the recorded noises. A keypad allows exceptional events to be marked during the ongoing measurement. These markers then appear in the graphs of the data in the Data Explorer. For remote, long-term unattended noise monitoring, the XL2 can be extended with the NetBox, and the level data viewed at any time through the NoiseScout website.
 

Gateway Noise Monitor Status
Gateway Noise Monitor Status


Automatic detection of Tonal or Impulsive sounds
The Data Explorer software graphically displays the level data and the 1/3rd-octave spectra; the audio file can be played in sync with the graph. This allows easy detection and marking of sounds that should be removed from the Rating Level calculation.

The software also automatically marks periods suspected of containing tonal or impulsive sounds. For the tonality, the KT penalty can be determined from the 1/3rd-octave spectrum or from the narrow-band FFT spectrum in accordance with the ISO 1996 standard. Based on this, Data Explorer calculates the Rating Level Lr. The limits vary from country to country.
 

XL2 Data Explorer
FFT and Tone Analysis
 

XL2 Data Explorer
Rating Level


Installation on any number of PCs
The Data Explorer software is the perfect tool for reworking the raw data captured by the XL2 Sound Level Meter to achieve the final Rating Level Lr. Data Explorer can be installed on any number of PCs. As an alternative to the permanent license, a low-cost annual subscription is also available. Software updates are free of charge for registered customers.

The recording of sound levels with impulse time-weighting and the storage of uncompressed wav files is made possible with the installation of the Extended Acoustic Pack Option on the XL2.

Categories: 騒音モニタリング

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