原帖由 Zend 於 4-7-2008 21:33 發表 ![](http://www1.nakuz.com/bbs/images/common/back.gif)
log is a special function
log(AB)=logA+logB
dB = 10log(I/Io)
when the intensity is doubled, we just add a factor of 2
i.e. 10log2 = 3.xx
therefore dB = 70+3.xx = 73
As a rule of thumb ...
亦都可以簡單諗
一個聲響都70dB, 兩個聲響冇可能仲細左或者等於
而140dB, 聽足一小時已經可以聾, 140dB實在太強
所以73dB是最有可能
詳細可參考ZEND的計算 |