Safety in practical lessons on SOUND and LIGHT

Loud sounds can damage the ear drum
High frequency sounds can cause nausea or headaches (especially when they are just in the supersonic range).
Flashing lights (such as in the stroboscope) can trigger epileptic fits. This happens most commonly at frequencies that are near to the alpha wave brain frequency, so girls may be fine at one frequency and then have problems at others!
Always make a class aware of the risk no matter how slight and encourage students to tell you if they feel uneasy or unwell when you are using light or sound.
As well as physical risks there are psychological ones:
When looking at the range of audible frequency the experiment might well reveal that some have a very restricted range. Be sensitive.
Similarly when using colour charts colour blindness may come to light!
See optics for safety when using of a laser in the laboratory

Extracted from WGHS Physiscs Department hHandbook written by L.O. Jones 2005