A clock, a fridge, a fan.
A steady floor within 26 dB of the voice is cleaned: “A steady noise floor was found, so it is removed.”
SOLIPSIUM Super resolution audio engine
Oral history
Clean up an oral history interview for listening.
Keep the original as your preservation copy, and drop a copy here. Solipsium measures its noise, hum and clipping before it changes anything.
Drop a copy of the interview
Solipsium checks it in your browser for clipping, hum and noise, without uploading it. It can then repair the first 20 seconds for you to hear, with no account.
WAV, MP3, M4A, MP4 and more, up to five minutes for the check.
Your first 20 seconds
After signing up, drop the same file into the editor to repair all of it.
What Solipsium hears
Make a free account to repair the whole recording
Then drop the same file into the editor. Scans and short repairs are free.
Two copies
A preservation copy and an access copy.
Archives keep the recording exactly as it was made, and make a second copy for people to listen to.
The preservation copy.
The interview as recorded, never edited, saved as a WAV beside its notes and the speaker's release form.
The access copy.
A copy repaired for listening: less noise, no hum, the level set for headphones. Name it so nobody mistakes it for the original.
A note of what changed.
The try lists a reason for each step it took. Copy those lines into the interview's notes.
Fault by fault
What a living room brings, and what is repaired.
The check in your browser names background noise, mains hum, clipping, dropouts and muffled sound, with their times.
A lamp or a charger.
Mains hum is notched out in bands 3 Hz wide: “Mains hum was found, so it is notched out before any cleanup.”
A bare room.
Echo reduction runs only when echo is the one thing found, with no steady noise, music, hum, clipping or muffled sound beside it. On a longer recording it works about 20 seconds at a time. The result reads: “Room echo seems to blur the speech, so echo reduction is used.”
A laugh that clipped.
Flat tops up to 10 ms long are partly raised back from the undamaged samples around them, never more than 2.3 dB over the clip level. A top that is unsafe to raise is left exactly as it was.
Questions
About oral history recordings.
Can the repaired copy go into the archive?
As an access copy, beside the untouched original. A repair is a changed file, and a treble rebuild adds sound labelled inferred.
Interviews on cassette?
Capture them first, as the cassette tape page describes, and keep the capture as the preservation copy.
An interview of two hours?
The check in your browser reads up to five minutes, and the editor imports up to 30 minutes and 1 GB at a time with a free account. Cut a longer recording into parts with the audio splitter and repair each part.
A family's own recordings?
The family recordings page covers voicemails, memos and old tapes of the people you love.
Many interviews at once?
A society or a library with a collection can read about the pilots on Solipsium for teams.
Is my recording uploaded?
Not for the check, which runs in your browser. Pressing Repair the first 20 seconds sends those 20 seconds; when your browser could not open the file, or it runs over five minutes, the file itself goes to Solipsium's server, so the try is offered for it only up to 25 MB. Solipsium keeps only the first 20 seconds and deletes them within an hour. If you are signed in, a file you drop or choose is uploaded to your account and opens in the editor instead. The privacy notice has the rest.
Free audio tools
Related free tools.
For tapes, long interviews and the file itself.
- Clean up a cassette tape
Capture an interview on tape and check it.
- Audio file info
Read a file's codec, rate, length and tags for the notes.
- Audio splitter
Cut a long interview into parts.
- Clean up a deposition recording
A copy repaired, the original kept as it was.
- All free audio tools
Every free tool on one page.
The whole interview.
Make a free account and drop the access copy into the editor to repair all of it, up to 30 minutes at a time.
Repair the access copy
Free account, no card.