Acoustic Signal Generator
Online Tone Generator: 20 Hz to 20,000 Hz Audio Frequencies
Generate mathematically pure sine, square, triangle, and sawtooth audio tones across the entire human hearing spectrum. Ideal for speaker calibration, audio equipment testing, hearing checks, and acoustic tuning.
Online Frequency Tone Generator
How to Generate Audio Tones Online
- Select your target frequency: Use the logarithmic slider for broad sweeps (20 Hz to 20 kHz) or fine-tune by ±1 Hz / ±10 Hz using the precision step buttons.
- Choose your waveform: Default to Sine wave for pure acoustic testing without harmonics. Select Square or Sawtooth for rich harmonic overtones, or Triangle for mild linear harmonics.
- Set safe volume and click Play: Keep headphone or speaker volume moderate (30%–50%) to protect your hearing, especially at high frequencies above 10 kHz.
Waveform Physics: Sine vs. Square vs. Triangle vs. Sawtooth
Sine Wave (Pure Fundamental)
Contains only the single fundamental frequency with zero harmonic distortion. Used as the global benchmark for audio equipment linearity, hearing threshold audiograms, and room acoustic resonance.
Square Wave (Odd Harmonics)
Alternates abruptly between positive and negative peak voltages. Contains all odd harmonics (3rd, 5th, 7th...) dropping at 1/n. Essential for testing digital amplifier slew rates and distortion.
Triangle Wave (Soft Harmonics)
Linear voltage rise and fall containing odd harmonics dropping steeply at 1/n². Produces a warmer, flutelike timbre ideal for acoustic modeling and gentle sub-bass testing.
Sawtooth Wave (All Harmonics)
Ramps smoothly upward before plunging instantly. Contains both even and odd harmonics dropping at 1/n, producing a bright, buzzing timbre common in subtractive analog synthesizers.
Standard Acoustic Reference Frequencies
- 440 Hz (Concert A / A4): The international musical pitch standard established by ISO 16 for acoustic instrument tuning and orchestra reference.
- 432 Hz (Verdi Pitch): An alternative scientific pitch tuning mathematically related to whole-integer vibrations, favored for ambient meditation and acoustic warmth.
- 1,000 Hz (1 kHz Reference): The universal audio engineering calibration tone used for broadcast level alignment, SNR measurement, and 0 VU reference.
- 165 Hz (Trapped Water Expulsion): The optimal resonant acoustic excursion frequency used by AudioSolver to dislodge trapped liquid droplets from micro-speaker meshes.
- 50 Hz / 60 Hz (Mains Electrical Hum): The electromagnetic AC power grid frequency used to diagnose electrical ground loops and unshielded cable hum.
Quick answers
Frequently asked questions
What waveforms can this online tone generator produce?
This tone generator produces mathematically pure sine, triangle, square, and sawtooth waves using the browser Web Audio API oscillator node with zero distortion and negligible latency.
Why is 440 Hz standard concert pitch?
440 Hz (A4) was officially standardized by the International Organization for Standardization (ISO 16) in 1955 as the universal reference pitch for acoustic instrument tuning and orchestral performance.
What is the difference between 432 Hz and 440 Hz?
432 Hz is an alternative philosophical and acoustic tuning system (Verdi tuning) favored by some artists for perceived natural resonance and warmth, whereas 440 Hz is the modern global standard for commercial audio.
Can I use this frequency generator to test human hearing limits?
Yes. Most healthy human ears hear between 20 Hz and 20,000 Hz. As humans age, high-frequency hearing naturally declines (presbycusis), so adults commonly stop hearing tones above 14,000 Hz–16,000 Hz.