SOLIPSIUMAlpha
SOLIPSIUM Super resolution audio engine
Lectures
Drop a recorded lecture or class here. Solipsium measures its noise, hum, clipping and gaps before it changes anything, and says what it found and when.
Drop a lecture recording here
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.
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.
Recording
Most of what goes wrong in a lecture recording is distance. Every metre between the lecturer and the microphone lets in more of the room.
Many schools and lecturers have rules about recording a class. Ask before you press record.
A phone on the front desk hears the lecturer more clearly than one in the back row. Where the lecturer wears a microphone, the room's sound system or its recorder holds the cleanest copy of the voice.
Drop the recorder's own file here, not a copy shared through a messaging app, which can shrink it. The phone's voice memo app is fine, and the online voice recorder records up to 30 minutes at a time in the browser.
Fault by fault
The check in your browser names background noise, mains hum, clipping, dropouts and muffled sound, and says when it hears each one. The try repairs the first 20 seconds on Solipsium's server and lists a reason for each step.
A projector fan or the room's air handling leaves a steady floor. A steady floor within 26 dB of the voice gets Full-band speech cleanup, a speech model that keeps the voice's full range and lowers what surrounds it. The result reads: “A steady noise floor was found, so it is removed.”
A lectern microphone run through an amplifier can carry mains hum. Lines at 50 or 60 Hz and its multiples that stand 10 dB over the frequencies around them are notched out in bands 3 Hz wide: “Mains hum was found, so it is notched out before any cleanup.”
A large hall smears the words into each other. 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 then reads: “Room echo seems to blur the speech, so echo reduction is used.”
Chatter around the recorder can be heard as other voices behind the speaker. When the try finds them, the result reads: “Other voices seem to sit behind the speaker, so speech cleanup is used.”
Cleanup can lower the noise around a distant voice, but it cannot move the voice closer. The check names a very quiet recording; make audio louder raises the level without cleaning it.
Questions
Yes, in parts. 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.
Speech cleanup lowers voices that sit behind the main speaker. A question asked next to the recorder can be the loudest voice in the room, and then it stays. Switch between Original and Repaired on the same words to hear what changed.
It can lower the noise and, when echo is the one thing found, the echo. What the microphone never picked up cannot be put back, so a lecturer who is hard to follow on the original can stay hard to follow.
No. It repairs the sound. Keep the original as well, since any repair is a changed copy.
A screen recording or a video of the lecture works: drop the MP4, MOV, MKV or WebM file, and the check reads its sound when your browser can open it. With a free account, the editor's video export keeps the original picture with the repaired sound.
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
For a long lecture, or one fault at a time.
Cut a long lecture into parts in your browser.
When room echo is reduced, and when it is not.
Chatter behind the speaker, lowered by speech cleanup.
Raise a quiet recording until its loudest peak reaches -1 dBFS.
Every free tool on one page.
Make a free account and drop the same recording into the editor to repair all of it, up to 30 minutes at a time.
Free account, no card.