Online Tone Generator

Generate Pure Audio Tones Instantly

Need to test your speakers, tune an instrument, or just annoy your dog? The Online Tone Generator creates precise audio frequencies right in your browser.

Select from Sine, Square, Sawtooth, or Triangle waves and sweep through the entire audible spectrum (20Hz to 20kHz). It's a simple yet powerful tool for audio engineers, musicians, and sound enthusiasts.

What is a Tone Generator?

A tone generator produces pure audio frequencies at specific pitches. Unlike music or speech (which contain multiple frequencies), tone generators create single-frequency sounds. This makes them essential for testing audio equipment, calibrating speakers, conducting hearing tests, and understanding sound physics.

Understanding Audio Frequencies

Frequency Basics

Frequency measures how many sound wave cycles occur per second, measured in Hertz (Hz). Higher frequencies produce higher-pitched sounds. 440Hz is the standard tuning note A4 in music. Doubling frequency raises pitch by one octave (440Hz → 880Hz = A5).

Human Hearing Range

Humans hear 20Hz (very low bass) to 20,000Hz (high treble). Infants hear the full range, but high-frequency hearing degrades with age. By 40, most people can't hear above 15kHz. By 60, the limit drops to 12kHz. Loud noise exposure accelerates hearing loss.

Musical Note Frequencies

Musical notes correspond to specific frequencies. A4 = 440Hz (orchestra tuning standard). Middle C (C4) = 261.63Hz. Each semitone up multiplies frequency by 1.059 (12th root of 2). Octaves double frequency.

Sub-Bass and Ultrasonic

Below 20Hz is sub-bass - felt more than heard (earthquakes, explosions). Above 20kHz is ultrasonic - used for dog whistles, medical imaging, and pest deterrents. Audio equipment often reproduces beyond human hearing for technical reasons.

Waveform Types

Sine Wave

Pure, smooth tone containing only fundamental frequency. No harmonics or overtones. Sounds clean and simple. Used for precise audio testing, hearing tests, and scientific measurements. Least harsh on ears at high volumes.

Square Wave

Harsh, buzzing sound with odd harmonics (3x, 5x, 7x fundamental). Sharp transitions create bright, aggressive tone. Used in synthesizers for bass sounds and retro video game music. Contains more energy than sine waves.

Sawtooth Wave

Bright, buzzing sound with all harmonics (2x, 3x, 4x fundamental). Richer than square wave. Classic synthesizer sound for leads and basses. Contains maximum harmonic content of basic waveforms.

Triangle Wave

Softer than square wave, containing only odd harmonics but weaker. Sounds hollow and flute-like. Used for mellow synthesizer tones. Gentler than square but more character than sine.

How to Use This Tone Generator

Step 1: Adjust frequency slider or use +/- buttons to set desired Hz
Step 2: Select waveform type (Sine, Square, Sawtooth, Triangle)
Step 3: Click "Play Tone" to start audio generation
Step 4: Adjust volume on your device (start low!)
Step 5: Click "Stop Tone" when finished

Common Applications

Speaker and Headphone Testing

Test frequency response by sweeping through range. Identify resonances, distortion, and frequency gaps. Compare left/right channel balance. Verify subwoofer crossover points. Professional audio engineers use tone generators for room acoustics analysis.

Hearing Tests

Determine hearing range and sensitivity. Start at comfortable volume with 1kHz. Gradually increase frequency to find upper limit. Test lower frequencies to find bass threshold. Audiologists use calibrated tone generators for professional hearing assessments.

Audio Equipment Calibration

Calibrate mixing consoles, equalizers, and processors. Set proper gain staging using reference tones. Align tape machines and analog equipment. Verify digital audio converters for accurate frequency reproduction.

Musical Instrument Tuning

Generate reference pitches for tuning instruments. A440 is standard orchestra tuning. Some orchestras use A442 or A443 for brighter sound. Electronic tuners use tone generators internally for pitch detection.

Sound Design and Synthesis

Create synthesizer patches starting with basic waveforms. Layer multiple frequencies for complex timbres. Design sound effects for games and films. Understand harmonic relationships in music production.

Tinnitus Masking

Some people use tone generators to match their tinnitus frequency. Matching tone can help mask ringing temporarily. Medical professionals use this for tinnitus diagnosis. Not a cure - consult audiologist for treatment.

Frequency Ranges and Uses

Sub-Bass (20-60Hz)

Felt more than heard. Requires subwoofers or large speakers. Used in movie theaters for explosions and rumble. Electronic music uses sub-bass for powerful low end. Excessive sub-bass causes listener fatigue.

Bass (60-250Hz)

Fundamental frequencies of bass instruments. Kick drums, bass guitars, low piano notes. Critical for music power and warmth. Too much muddies mix, too little sounds thin.

Low Mids (250-500Hz)

Body of guitars, lower vocals, snare drums. Often problematic frequency range - buildup causes muddiness. Careful EQ needed. Important for instrument fullness without cloudiness.

Mids (500Hz-2kHz)

Core of most instruments and vocals. Human ear most sensitive here. Telephone bandwidth (300-3400Hz) covers this range. Critical for speech intelligibility and music clarity.

Upper Mids (2-4kHz)

Presence and definition. Vocal consonants, guitar attack, snare crack. Boosting adds clarity but can cause harshness. Most important range for mixing - makes elements cut through.

Presence (4-6kHz)

Vocal presence and instrument attack. Boosting makes sounds closer and more intimate. Excessive boost causes listening fatigue. Critical for broadcast and podcast clarity.

Brilliance (6-20kHz)

Air, sparkle, and shimmer. Cymbals, vocal breathiness, acoustic guitar sparkle. Too much sounds harsh and sibilant. Proper amount adds professional sheen.

Audio Testing Techniques

Frequency Sweep

Slowly increase frequency from 20Hz to 20kHz. Listen for volume inconsistencies, distortion, or dropouts. Reveals speaker frequency response problems. Professional sweeps use logarithmic progression matching human hearing.

Left/Right Channel Testing

Generate tone in one channel only. Verify proper stereo separation. Identify reversed polarity or wiring issues. Essential for studio monitor setup and headphone quality control.

Phase Testing

Play identical tones in both channels. Reverse polarity of one channel. If sound disappears, channels are in phase. If sound gets louder, channels are out of phase. Critical for speaker placement.

Distortion Detection

Play pure sine wave at moderate volume. Listen for buzzing or rattling indicating distortion. Increase volume gradually to find distortion threshold. Reveals speaker damage or amplifier clipping.

Room Resonance Finding

Play low frequencies (30-100Hz) at moderate volume. Walk around room listening for volume changes. Loud spots indicate resonance peaks. Helps position bass traps and acoustic treatment.

Safety and Hearing Protection

Volume Warnings

Always start at low volume. Sudden loud tones can damage hearing permanently. Especially dangerous at high frequencies (above 10kHz). Use volume controls carefully - digital audio can produce damaging levels.

Exposure Limits

85dB for 8 hours is safe limit. 100dB safe for only 15 minutes. 115dB causes immediate damage. Tone generators can easily exceed safe levels. Use SPL meter to monitor volume.

Headphone Risks

Headphones deliver sound directly to eardrums. More dangerous than speakers at same volume. Can't escape loud sound quickly. Always test with speakers first, then carefully try headphones.

High Frequency Danger

High frequencies (above 8kHz) damage hearing without seeming loud. Ear's protective reflex doesn't engage. Prolonged exposure to ultrasonic frequencies causes fatigue and headaches.

Technical Specifications

Sample Rate

Digital audio sample rate determines maximum frequency. 44.1kHz (CD quality) reproduces up to 22.05kHz. 48kHz (professional standard) reaches 24kHz. Higher sample rates (96kHz, 192kHz) used for processing headroom, not audible improvement.

Bit Depth

16-bit provides 96dB dynamic range (CD quality). 24-bit offers 144dB (professional recording). Higher bit depth reduces quantization noise. Tone generators benefit from high bit depth for pure tones.

Harmonic Distortion

Pure sine wave should contain only fundamental frequency. Harmonics indicate distortion. Total Harmonic Distortion (THD) measures this. Good audio equipment has THD below 0.1%. Tone generators test THD in amplifiers and speakers.

Signal-to-Noise Ratio

Ratio of desired signal to background noise. Higher is better. 90dB SNR is good, 100dB is excellent. Tone generators help measure SNR in audio systems.

Musical Applications

Tuning Reference

A440 is international standard. Some orchestras prefer A442 or A443. Baroque music often uses A415. Generate reference pitch for tuning instruments without electronic tuner.

Interval Training

Generate two frequencies to hear musical intervals. Perfect fifth = 3:2 ratio (440Hz and 660Hz). Octave = 2:1 ratio. Helps musicians develop relative pitch recognition.

Beat Frequency

Play two slightly different frequencies (e.g., 440Hz and 442Hz). Hear beating at 2Hz (difference). Used for fine tuning instruments. Piano tuners use beats to set temperament.

Harmonic Series

Generate fundamental and harmonics (2x, 3x, 4x frequency). Understand overtone structure of musical instruments. Explains why instruments sound different playing same note.

Troubleshooting

No Sound Output

Check: Device volume, browser permissions, audio output selection
Solution: Ensure browser has audio permission, check system sound settings
Note: Some browsers block audio until user interaction

Distorted Sound

Cause: Volume too high, speaker damage, amplifier clipping
Solution: Reduce volume, test with different speakers
Prevention: Always start at low volume

Can't Hear High Frequencies

Normal: Age-related hearing loss above 15kHz is common
Check: Test with younger person, verify speaker capability
Note: Laptop speakers often can't reproduce above 16kHz

Tone Cuts Out

Cause: Browser tab backgrounded, power saving mode
Solution: Keep browser tab active, disable power saving
Alternative: Use dedicated audio software for long tests

Advanced Uses

Acoustic Treatment Testing

Generate problem frequencies to test acoustic panels. Play bass frequencies to verify bass trap effectiveness. Use pink noise (all frequencies) for overall room response.

Microphone Calibration

Generate known frequency and level. Measure microphone output. Calculate frequency response curve. Professional calibration uses multiple frequencies and SPL levels.

Crossover Alignment

Test speaker crossover points. Generate crossover frequency (e.g., 80Hz for subwoofer). Verify smooth transition between drivers. Adjust crossover settings for flat response.

Noise Cancellation Testing

Generate test tones to evaluate active noise cancellation. Measure cancellation effectiveness at different frequencies. Most ANC works best 50-1000Hz.