SOLIPSIUMAlpha
SOLIPSIUM Super resolution audio engine
Muffled audio
Solipsium rebuilds the treble a phone line cut off, from the sound below it, and labels what it adds as inferred. See where your recording stops, then hear the first 20 seconds repaired.
Drop a muffled recording here
Solipsium checks in your browser where its sound stops and what else is wrong, without uploading it. It can then repair the first 20 seconds for you to hear, with no account.
WAV, MP3, M4A, video and more, up to five minutes.
After signing up, drop the same file into the editor to repair all of it.
Then drop the same file into the editor. Scans and short repairs are free.
How it works
A phone line or a low-bitrate call cuts the sound off above about 4 kHz. A pocket or a mask dulls the treble and lets some of it through. The check in your browser says where your recording's sound stops.
When the sound stops under about 5.4 kHz and nothing else is found, AP-BWE's 8 kHz model predicts the treble from the sound below 4 kHz. The try's result then reads: “Little sound was found above 4 kHz, like a phone line. The treble is rebuilt from the sound below it, which is kept as it was. What is added is inferred.” It runs on Solipsium's server processor, so the free try does it too.
A phone line with a steady noise floor gets gentle cleanup before the rebuild, and the result reads: “A phone line with a steady noise floor was found, so gentle cleanup runs first, then the treble is rebuilt from the sound below 4 kHz. What is added is inferred.”
A recording whose sound stops between about 5.4 and 8.3 kHz gets no rebuild, and the try's result can read: “The treble is thin, but real sound reaches above a phone line, so it is kept as it is. The treble rebuilder is used only on phone lines.” A file saved at 16 kHz, which stops at or a little above 8 kHz, has a rebuild of its own on the audio upscaler page.
Questions
As an estimate. The model predicts treble from the sound below 4 kHz and puts it above, and the result labels it inferred. Below 4 kHz you hear your own recording.
The rebuild needs sound that stops under about 5.4 kHz, with nothing else found or only steady noise. Clipping, dropouts or hum found alongside are repaired and the treble stays as it was. With noise and other damage together, or room echo or other voices behind the speaker, the try says: “Speech cleanup is not run on narrow-band audio: it measured worse than leaving the recording as it is.” The try lists its reasons beside the result.
That depends on where its sound stops, which the check shows. Under about 5.4 kHz it is treated as a phone line. Between 5.4 and 8.3 kHz nothing is rebuilt. Between 8.3 and 11 kHz it is treated as a file saved at 16 kHz, as on the audio upscaler page. When steady background noise is the only other fault, it is cleaned.
Yes, when its sound stops where a phone line's does. The check shows where yours stops before anything is sent.
Solipsium's free try is built for speech. For music, a free account's editor can run AudioSR on a passage of up to 60 seconds, and what it adds is inferred.
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
Pages for other narrow recordings, and a tool that draws where the sound stops.
Rebuild the treble of speech saved at 16 kHz, labelled inferred, and hear 20 seconds free.
Save a voicemail from an iPhone or Android phone, then check it and hear 20 seconds repaired.
Check an iPhone or Android memo for noise, hum and clipping, then hear 20 seconds repaired.
See a spectrogram of a file and where its sound stops, made in your browser.
Why earbuds record muffled sound.
Every free tool on one page.
A free account's editor runs the same Suggested repair over recordings up to 30 minutes long.
Free account, no card.