Test the frequency response of headphones and speakers with this free online sound frequency tool. Generate tones across 20 Hz to 20 kHz and choose from sine, square, sawtooth and triangle waveforms. The separate left and right output modes help with stereo and ear comparisons, while the 20 Hz to 20 kHz sweep can reveal noticeable peaks, dips and resonance in playback equipment or rooms. https://aitoolspros.com/tools/audio/tone-generator/