What is the normal human hearing range?

Many people can hear frequencies roughly between 20 Hz and 20,000 Hz in ideal conditions. High-frequency hearing sensitivity naturally decreases with age and prolonged exposure to loud noises.

Why can't I hear the 20 Hz tone?

Most smartphones and basic laptop speakers cannot reproduce ultra-low bass frequencies. A dedicated subwoofer or high-quality headphones are usually needed to hear 20 Hz, and even then, it is often felt rather than heard.

Which waveform should I use?

Start with a Sine wave for clean testing and instrument tuning. Use Sawtooth or Square waves at a very low volume when you want to expose speaker distortion, cabinet rattles, or buzzes.

Why does the same frequency sound different on each device?

Different speakers have unique frequency response curves. Additionally, smartphones and computers apply internal audio processing, EQ, or loudness normalization. Bluetooth connections can also alter the timing and tone.

Is this safe for my phone speaker?

Generally yes, provided you keep the volume low and perform short tests. Avoid long, continuous sessions at maximum volume, especially with harsh waveforms at extreme high or low frequencies.

Online Frequency Generator (Tone Generator)

Free Online Tone & Frequency Generator

A frequency generator is a simple tool that creates a steady audio tone at a chosen pitch. You set the frequency in Hertz (Hz). For example, A4 is 440 Hz, which means the sound vibrates 440 times per second.

This page acts as a web-based tone generator that runs directly in your browser using the Web Audio API. You can change the pitch and volume live without downloading any files.

Quick 3-Step Guide

Start at Low Volume: Always lower your system and tool volume to 10% before pressing Play to protect your hearing and equipment.
Set the Frequency: Enter a specific Hz value or use the slider to sweep across the frequency band.
Select a Waveform: Choose Sine for a pure tone, or Square/Sawtooth to test for speaker rattling and distortion.

Who is this useful for?

Musicians: Match a reference note while tuning instruments by ear.
Audio engineers: Perform fast level checks and spot obvious speaker phase drop-offs.
Gamers & Streamers: Check if a headset has a channel imbalance or a dead side.
DIY Repair: Find rattles, buzzes, or loose parts in speaker cabinets. Try our Speaker Cleaner Tool for liquid damage.

Waveforms Explained

The choice of waveform changes how the tone feels and how your speaker reacts mechanically. Some shapes sound smooth, while others sound harsh and are rich in harmonics.

Sine: Clean and smooth. Best for simple testing, hearing checks, and tuning by ear.
Square: Very sharp and loud-feeling. Useful to expose distortion quickly in low-end setups.
Sawtooth: Bright and buzzy. Excellent for finding mechanical rattles and room resonances.
Triangle: Softer than square, but richer than sine. A middle ground for general checks.

Real-World Examples & Sweep Testing

Here are practical frequency ranges you can try. Always start at a low volume and increase slowly.

20–60 Hz: Test sub-bass capability. Many smartphone speakers physically cannot reproduce this range.
60 Hz: Check for mains hum or electrical grounding issues in an audio setup.
100–200 Hz: Spot cabinet rattles or desk vibrations caused by bookshelf speakers.
440 Hz: Standard tuning reference for many musical instruments (A4).
1,000 Hz (1 kHz): A common “reference tone” for quick volume level matching.
8–12 kHz: Check if tweeters output clean highs without static buzzing.
10–18 kHz sweep: Explore your personal high-frequency hearing range (keep volume extremely low to avoid pain).

Accuracy & Hardware Limitations

While the frequency value generated is mathematically precise inside the browser engine, what you actually hear depends heavily on your hardware. Phone and laptop speakers often cannot reproduce deep bass (below ~100 Hz) and struggle above 15 kHz. Additionally, your operating system or Bluetooth headphones may apply built-in EQ, compression, or loudness normalization that alters the raw tone.

Frequency Generator