The formulas for sound wave intensity and decibel levels are presented in the window below. The animated bar chart on the right shows the intensities of common sounds including those produced from the rustle of leaves, a train, and a jackhammer.
The intensity demonstration is shown in the window below. The physics student is directed to select various combinations of medium, frequency, and amplitude, and to observe the effects of these variables on the overall intensity and decibel levels. If the decibel level exceeds 110 dB, a breaking glass sound is heard and an image of a wine glass shatters as shown below. The values of the intensity and decibel levels are computed and displayed to the right of the wine glass.
To listen to breaking glass, press the sound button for the appropriate audio format.