Check audio equipment and generate reference tones with a free online tone generator. Adjust frequency from 20 Hz to 20 kHz, select sine, square, sawtooth or triangle waveforms, and control output between both ears, left ear or right ear. It can help with speaker testing, headphone checks, instrument tuning, room resonance testing and general audio troubleshooting. https://aitoolspros.com/tools/audio/tone-generator/