Definition 21.7 High School Physics · 第 21 章 — Sound and Acoustics The sound intensity III is the acoustic power crossing one square metre facing the wave: I=P/SI = P/SI=P/S, in W/m2\mathrm{W}/\mathrm{m}^{2}W/m2. The quietest audible sound is about I0=1.0×10−12 W/m2I_0 = 1.0 \times 10^{-12}\,\mathrm{W}/\mathrm{m}^{2}I0=1.0×10−12W/m2; pain begins near 1 W/m21\,\mathrm{W}/\mathrm{m}^{2}1W/m2. 在原文中阅读 →