Scratch Detection
Find every scratch, track by track.
While you play a record in a Silent Session, Spinstack listens through the microphone for surface scratches and builds a per-record map of where they are, track by track. Analyzed live on your device. A spot becomes Confirmed once it recurs at the same place across plays.
Per‑track
Mapping
100%
On‑device
Opt‑in
Off by default
Experimental Spinstack Labs feature · off by default
Step by step
How it works
Turn it on in Spinstack Labs
Open Settings, Spinstack Labs, Scratch Detection. It is off by default, so nothing listens until you opt in.
Start a Silent Session and drop the needle
Play a record while a Silent Session is open in the foreground. Spinstack listens through the microphone and analyzes the audio live on your device.
Surface scratches get placed, track by track
As the record plays, the detector listens for the signature of a surface scratch and pins each one to a position on the record, grouped by track.
The music gets matched to the moment
When Spinstack can match the audio to Apple Music, each scratch is pinned to the exact track and time. When it cannot, the position is estimated from track lengths and marked with a clock icon.
Repeat plays confirm a spot
A tentative mark becomes Confirmed once it recurs at the same place across plays. Real defects rise to the top; one-off noises fade away.
Open the Scratch Map from any played release
Every record you play gets a Scratch Map in its ⋯ menu, with spots grouped by track. Tap one to confirm it, or set a confirmed spot back to tentative.
Per record
The Scratch Map
Each played release keeps its own map of where the surface damage lives. It is the difference between knowing a record "has a scratch somewhere" and knowing it sits forty seconds into side B, track three.
Tentative or Confirmed
Tap a spot to confirm it, or set a confirmed one back to tentative. You stay in control of what counts.
Exact time or estimate
With an Apple Music match, a scratch pins to the precise track and time. Without one, a clock icon marks an estimate from track lengths.
Hear the moment
If a verification clip was saved, a play button lets you listen to that exact moment and judge it for yourself.
Grouped by track
The map organizes spots track by track, so a record's condition reads like a table of contents, not a guess.
Architecture
How the pipeline works
Every stage runs on your device. The microphone audio is analyzed live and is never uploaded.
Private by default
On your device, on your terms
Analyzed on-device
Audio is processed live on your iPhone. Nothing about the sound is uploaded.
Off until you ask
Disabled by default. It only listens while a Silent Session is open in the foreground, after you opt in.
Recordings stay local
Optional verification clips live on your device, are not backed up, and you can delete any or all of them anytime.
Contribute to research, only if you want to
You can anonymously contribute clips you have labeled to help train better detection. This is off by default, and a consent screen spells out exactly what is and is not sent. You hear every clip before it goes, and you can withdraw everything at any time.
Only the clips you tap Contribute on, with your label
Never your identity or your account
A few on-device numbers about the sound
Never which record it was
This one is early
Scratch Detection is a true experiment. Real scratches should map reliably, but the detector is tuned to catch more rather than miss, so drum-heavy or loud passages can still false-flag. That is exactly what the verification recordings and your labels are for. Flag anything that feels wrong, and the model gets sharper. Send notes any time to labs@spinstackios.app.
Requirements
What you need
The latest version of Spinstack
Scratch Detection lives in Spinstack Labs
An iPhone microphone and a Silent Session
Detection runs while a Silent Session is open in the foreground
Opt in from Spinstack Labs
Settings, Spinstack Labs, Scratch Detection. Off by default
Apple Music, optional
A match pins scratches to the exact time. Without it, positions are estimated
Shape it with us.
Scratch Detection is a Spinstack Labs experiment, off by default. Turn it on, try it on a record you know well, then tell us what it gets right and wrong.
Download on the App StoreFind it in Settings, Spinstack Labs, Scratch Detection