One family of sounds

Tap each card below with sound on. Five different jobs, and yet they clearly come from the same product. That is not luck. They are all the same small struck bar, played higher, lower, shorter or longer.

A product's sounds work like a typeface. One family, several weights. Five sounds from one material feel like a product; five sounds from five packs feel like clip art.

Pick one material

Start with a physical thing, not a style. "A felt mallet on a wooden bar." "A fingernail on thin plastic." "A muted glockenspiel." Every sound in the family is that thing, struck differently.

Apple's sound team works this way: they record real instruments like marimba and kalimba, and once tapped a hollow watch case with mallets to find its ring. Real materials make new technology feel familiar. The default AI failure is the opposite: a glossy sci-fi "digital blip" that belongs to no product.

The grammar of a family

Meaning comes from the shape of the sound. People learn it in a handful of hearings.

Notice the cards above: send rises, error falls and clashes, success is the only one with three notes.

A family is small

Most products need four to six sounds, not forty:

• tick for a toggle, a selection, a snap. One hit, 80 ms or less, high.
• tap for a press, only in products built to feel physical. Up to 120 ms.
• send for sent, saved, done. One or two rising notes, up to 250 ms.
• receive for an incoming message. Two notes, lower than send, up to 400 ms.
• error for a rejected submit. Low, falling, up to 200 ms, beside a shake.
• success for a rare milestone. Three notes, up to 800 ms.

Write the family down as a list before generating anything. It is your sound design system.

Design a sound family for this product before making any audio.
Pick ONE physical material (for example "soft felt mallet on a small wooden bar") and derive every sound from it.
List 4-6 sounds max as a table: name, role, contour (rising/falling), notes or pitch, duration in ms.
Rules: small/frequent = high, short, single hit; rising = success; falling and dissonant = error; only rare milestones get 3 notes.
No stock UI packs, no sci-fi blips.

The numbers

Most "this sound feels wrong" complaints are a spec miss, not a taste miss: too long for its animation, too loud next to speech, or a sliver of silence before the hit.

A handy rule from Toptal: a sound should not outlast the animation it goes with by more than about 300 ms. A 120 ms press with an 800 ms tail is a bell, not feedback.

Loudness. Taps and ticks sit around −18 to −14 LUFS, below speech and above silence. Notifications may go to about −12. Peak every file at −3 dBFS so it never clips. Put the design level in the file and the person's level in the volume control; never bake "a bit quieter" into the asset.

Format. Mono, 44.1 kHz. Phones and laptop speakers fold stereo into mono anyway. Keep a WAV as the master and ship MP3 or Opus. Trim the start to the first audible sample: five milliseconds of silence up front is a visible sync error. Fade the last 10 ms so it ends without a click.

Shape. Cut everything under 150 to 200 Hz; laptop speakers cannot play it and it only eats headroom. Keep the body between 500 Hz and 4 kHz, where every device is honest.

What a designed effect is made of

For films and marketing pieces, Leon Lin's earshot project measured dozens of professional sound effects and found the same habits again and again:

1. One gesture each. A pitch that sweeps, notes that step up, a gate that speeds up into the cut.
2. Its own frequency band. Typing has nothing low; impacts live low with a thin tick on top. The middle is left for voice and music.
3. A hard end. Short sounds hold, then stop. No long reverb ride-out.
4. Mono for objects, wide for textures. A click is mono; a shimmer can be wide.
5. Placed by kind. Clicks land their attack on the moment; a whoosh peaks on the fastest frame; a riser ends on the hit.

Repeated sounds vary in take (four recordings cycled, a tiny level change) rather than random pitch. The UI click is the exception: one voice, one level, every time.