Tone generators are used for: speaker calibration, hearing tests, room acoustic analysis, tuning musical instruments, testing audio equipment, and science experiments.

Sine waves are pure single-frequency tones — best for calibration and testing. Square waves contain odd harmonics, useful for testing transient response. Sawtooth has all harmonics and sounds brighter.

Prolonged exposure to loud high frequencies (above 10kHz) can cause hearing damage. Keep volume moderate. Above 15kHz, many adults can't hear the tone — that's normal age-related hearing loss.