What Is a Frequency Generator?
A frequency generator, also called a tone generator, produces a pure audio signal at an exact frequency you choose, measured in hertz (Hz) — the number of sound wave cycles per second. Tunerium's version runs entirely in your browser using the Web Audio API, letting you dial in any frequency from 20 Hz up to 20 kHz, pick a waveform, and play it instantly with no downloads or plugins.
Understanding the Frequency Range
Human hearing spans roughly 20 Hz to 20,000 Hz, though the practical range narrows with age — most adults lose sensitivity to the highest frequencies over time. Musically, this range covers everything from the deepest sub-bass to sounds well above the highest notes on a piano.
| Range | Approx. Hz | What it covers |
|---|---|---|
| Sub-bass | 20–60 Hz | Felt as much as heard; lowest piano and organ notes |
| Bass | 60–250 Hz | Bass guitar, kick drum, low male voice |
| Midrange | 250–4,000 Hz | Most vocals and instruments, speech clarity |
| Presence | 4,000–6,000 Hz | Clarity, articulation, "edge" of a sound |
| Brilliance | 6,000–20,000 Hz | Air, sparkle, cymbal shimmer, highest overtones |
How to Use This Frequency Generator
- Drag the slider or type an exact value into the number field to set your target frequency.
- Choose a waveform — sine for a pure, single tone, or square, sawtooth and triangle for harmonically richer test signals.
- Set the volume low to start, then click Play Tone.
- Adjust the frequency live while the tone plays — it updates smoothly without needing to stop and restart.
- Use the frequency sweep panel to automatically glide from one frequency to another over a set duration, useful for checking a speaker's full response range in one pass.
Common Uses for a Tone Generator
- Speaker and headphone testing — sweep through the range to listen for dead spots, rattles, or distortion at specific frequencies.
- Subwoofer and crossover checks — play low frequencies to find where your sub starts rolling off.
- Reference pitch — generate an exact frequency like 440 Hz to tune an instrument or check another tuner's accuracy.
- Room and system checks — some frequencies excite room resonances or rattles that are hard to hear otherwise; a steady tone makes them obvious.
- Casual hearing range checks — playing a sweep toward 15–20 kHz gives an informal sense of your high-frequency hearing, though this is not a substitute for a professional hearing test.
Waveforms Explained
A sine wave contains only a single frequency and sounds like a pure, clean tone — the standard choice for precise pitch reference or speaker testing. Square, sawtooth and triangle waves all contain the same fundamental frequency plus additional harmonic overtones layered on top, which is why they sound buzzier or brighter — useful for testing how a system handles more complex, harmonically rich signals rather than a single isolated tone.
Using a Tone Generator Safely
- Always start at low volume. Increase gradually rather than guessing and turning it up too far.
- Be extra cautious with high frequencies. Loud tones above about 2 kHz can feel uncomfortable or sharp well before they feel "loud" in the way bass does.
- Take breaks during sweeps. If you're testing across the full range repeatedly, give your ears rest between passes.
- Keep headphone volume conservative. Tones played directly into your ears feel louder than the same volume through speakers.
- This is not a medical device. Use it for audio testing and reference purposes, not for diagnosing hearing conditions.
Frequently Asked Questions
What frequency range can humans hear?
Most young, healthy ears can hear roughly 20 Hz to 20,000 Hz. Sensitivity to the highest frequencies typically declines with age.
What is a frequency generator used for?
Common uses include testing speakers and headphones, checking subwoofer response, tuning instruments to a precise reference pitch, and informal listening checks.
Is it safe to listen to test tones at high volume?
No — start at low volume and increase gradually. Loud tones, especially at high frequencies, can cause discomfort or hearing damage. This tool is not a medical device.
Is this frequency generator free to use?
Yes. It runs entirely in your browser using the Web Audio API and is free, with no downloads or account required.