Online Frequency Sound Generator – Pure Tones & Sweeps

A frequency sound generator is a tool that produces pure audio tones at specific frequencies measured in Hertz (Hz). It uses your device's audio hardware and the Web Audio API to generate precise sine, square, sawtooth, or triangle waveforms. These tools are used for audio testing, tuning instruments, sound therapy, scientific demonstrations, tinnitus relief, and meditation practices.

A pure tone is a sound with a single, constant frequency and a sinusoidal waveform — the simplest form of sound. Unlike musical notes from instruments (which contain harmonics and overtones), pure tones have no additional frequency components. They sound clear, smooth, and "electronic." Pure tones are essential for hearing tests, audio calibration, and understanding acoustic principles.

A frequency sweep (or chirp) gradually transitions from one frequency to another over a set duration. Linear sweeps change frequency at a constant rate, while logarithmic sweeps change exponentially — matching how human hearing perceives pitch. Sweeps are used for testing speaker/headphone frequency response, identifying room resonances, ear training, and audio equipment diagnostics.

Sine wave: The purest tone — smooth, mellow, no harmonics. Square wave: Hollow, bright sound rich in odd harmonics — resembles old video game sounds. Sawtooth wave: Buzzy, bright, contains both even and odd harmonics — classic synth lead sound. Triangle wave: Softer than square/sawtooth, with only odd harmonics that decay faster — flute-like quality. Each waveform has a distinct timbre despite being at the same frequency.

432 Hz is often called the "Verdi tuning" or "natural frequency" — some believe it's mathematically aligned with the universe and promotes relaxation. 528 Hz is known as the "Love frequency" or "DNA repair frequency" in sound healing communities, part of the ancient Solfeggio scale. While scientific evidence for specific healing properties is limited, many people find these frequencies pleasant and calming. Standard concert pitch is 440 Hz (A4).

You should always exercise caution. Pure tones concentrate all acoustic energy at a single frequency, which can cause hearing fatigue or damage more quickly than broadband sounds — especially at high volumes or high frequencies (above 8 kHz). Always start at low volume (below 50%), avoid prolonged listening above 85 dB, and stop immediately if you experience discomfort, ringing, or ear pain. This tool is for educational and testing purposes.

The average healthy young adult can hear frequencies from approximately 20 Hz to 20,000 Hz (20 kHz). However, this range narrows with age — adults over 50 often can't hear above 12–15 kHz. Below 20 Hz is infrasound (felt more than heard), and above 20 kHz is ultrasound. Individual hearing varies significantly, so use this generator to discover your personal hearing range.

Yes! This frequency generator works on all modern devices including smartphones and tablets. It uses the Web Audio API supported by Chrome, Safari, Firefox, and Edge. On iOS devices, you may need to tap the Play button once to enable audio (due to Apple's autoplay policy). For best results, use headphones or external speakers, as mobile built-in speakers typically can't reproduce very low frequencies (below ~200 Hz).