Audio Files Out of Sync

Me and 2 of my friends tried to record a podcast last night. One of my friends recorded on his PC with audacity, and my other friend recorded his audio file on his phone. We all started our recordings at the same time, however when I put all of theirs into an audacity project on my computer the files get out of sync the farther you go into the project. I am not sure how to fix this, and would appreciate any help or advice. I am on Windows 10.0.19042 and Audacity version 3.1.2.

You can use the [u]Change Speed Effect[/u]. There are several ways to enter the desired change and in your case you can enter the New Length.

…Every device has it’s own clock (oscillator) and no clock is perfect. So, the sample rate (44,100Hz, etc.) is usually off by a little and the two different devices will never match perfectly. Clock/speed errors also create pitch errors which is a problem for musicians.

In your case, I’d guess the biggest problem is the “cheap” soundcard/soundchip built-into the computer. USB audio interfaces are usually more accurate than consumer soundcards and the phone is probably also better than the soundcard.

…Pros use a super-accurate master clock (sometimes an atomic clock). In most situations the absolute accuracy isn’t that critical, but having a master clock (and devices that can use an external master clock) means that multiple devices are exactly matched down to the exact-sample i.e. At 44.1kHz, that’s 1/44,100th of second no matter how long the recording is.