Tone Generator: Hz & Noise

Any frequency, clean and precise. Every feature free.

Tone Generator: Hz & Noise plays pure test tones, five noise colours and frequency sweeps through a native audio engine built for clean sound: no clicks when you change a value, no aliasing on square and sawtooth waves, no distortion at full volume. For speaker and subwoofer tests, room and audio calibration, tuning by ear, hearing checks, electronics and science lessons.

TONE
• From 1 Hz to 22 kHz in steps of 0.01 Hz.
• Sine, square, triangle and sawtooth. Square, triangle and sawtooth are band-limited, so high tones stay clean.
• A large logarithmic dial: turn the inner wheel for smooth changes (one turn is an octave), drag the outer ring to jump anywhere.
• Fine steps: ÷2 and ×2 (octaves), ±1 Hz and ±0.1 Hz, or tap the number and type it.
• Note mode: pick a note and octave, step by semitones and cents, with A4 adjustable from 415 to 466 Hz. Note names in letters, German (H) or Do Re Mi.
• Every change glides smoothly, without clicks or pops.

NOISE
• White, pink, brown, blue and violet noise, all at the same level, for speaker tests, masking, sleep and focus.

SWEEP
• From one frequency to another in 5 seconds to 10 minutes, linear or logarithmic, once or in a loop, with a live graph and the current frequency.

TEST TOOLS
• Left, right or both channels, balance, and polarity inversion on the right channel to check that your speakers are wired in phase.
• Extra tones: add up to three tones for beats and chords, with the beat frequency shown.
• Bursts: pulse the sound with a period from 20 ms to 5 s and an adjustable duty cycle.
• Sleep timer, from 1 minute to 2 hours.
• A small oscilloscope draws the real generated wave.

PRESETS AND FAVOURITES
• A4 440, 432 and 442 Hz, 1 kHz calibration, 60 Hz sub test, 50 and 60 Hz mains hum, middle C, and hearing checks at 8, 12, 15 and 17 kHz.
• Save your own tones as favourites and recall them with one tap.

SAFE FOR EARS AND SPEAKERS
• Every start fades in from silence. A volume limit you choose, and a warning before a loud first play.
• A note tells you when a phone speaker may not reproduce a very low or very high tone.
• The sound stops when headphones are unplugged or a call comes in.

FREE AND PRIVATE
No ads, no in-app purchases, no subscription, no account. Works offline, no microphone, no data collected: your favourites stay on your device.

This app is not a medical device: the hearing checks are not a hearing test.

Dark and light theme, 71 languages.

Made by FELICE MARRA / MUSIC STUDIOS.