Pitch and Tempo issue on recording changes mid recording

Hi Guys,

New to the forum and I’m a bit of a novice with software so please be patient!

I record a podcast and twice now Audacity mid recording has changed the pitch and tempo of my recording so that it sounds like a chipmunk.

The first time was a pain and I assumed I had hit a hot key on the keyboard (ultimately I reduced the tempo by about 59% and the pitch by 22% and it allowed us to hear what the audio actually was. Unfortunately there was a significant amount of static on the recording which meant that I had to re-record that part of the podcast (tried using noise reduction but still wouldn’t allow the audio to be usable.)

The same thing has happened again (Static present, tempo increased, pitch too high) but the last hour of the file now sounds as though it’s underwater and has a significant echo on it (after reducing the tempo and pitch.)

Can anyone give me advice as to what the issue is to prevent it happening again and can anyone advise on how to fix the audio to be usable or at least to hear what was said so I can re-record?

Many thanks all.

Audacity Software version 2.3.3
Mic Beecaster
Windows Surface Pro

You’re probably getting [u]dropouts[/u]. If there are lots of little missing parts in the recording it will play back faster and you’ll get glitches noise.

There are some troubleshooting hits [u]here[/u].

It can be complicated but it’s related to multitasking interrupting the audio. It’s best if you don’t run other applications while recording and you can try to minimize any background operations. Your operating system is ALWAYS multi-tasking even if you are running only one application and there are recording & playback buffers (like storage tanks) that try to keep the audio flowing smoothly in & out when everything is working “nicely”.

Appreciate it. I’ll need to have a look at what’s running in the background as it’s only happened twice out of over a dozen recordings with the laptop running the same programmes in the background.

Any thoughts on how to bring the file back to how it should sound?

Any thoughts on how to bring the file back to how it should sound?

No. The missing bits were never recorded. If you have a few glitches sometimes they can be “repaired” but you’ve got a pretty-bad problem. :frowning:

The fact is, most recording problems can’t be fixed, especially not the bad problems…

The whole recording is there, (turns out instead of amending tempo and pitch I can change the speed which does both.) It now just has a lot of low static in the recording, I’ve tried to use a silent part of the recording and noise reduction but it’s still present.

The whole recording is there,

Little bits of the waves missing. You can stretch-out the waves to get the timing & pitch back (approximately) but wherever there is a missing piece you get a glitch (discontinuity) and distortion/noise.

it’s only happened twice out of over a dozen recordings with the laptop running the same programmes in the background.

Aren’t erratic problems just the most fun?

It’s not just programs running in the background. It’s the new Supervisory Programs that may, at any time decide they need sound services more than you do. This is a problem with Skype, Zoom, and other chat programs. They take over the computer when they’re running in order to work right. There is no option and sometimes they leave little bits of themselves running even after they close.

I can make this worse. Since you’re on Windows, it’s possible you’re not the only user on your machine. Is your virus protection up to date? When was the last time you did that deep virus check that runs all night?

Koz

Apologies I see what you mean now. Appreciate the help. I think going forward it’s probably easiest to run an absolute minimum amount on the computer and use a secondary computer for other things we use during the podcast like Chrome searches.

Oh the randomness is the killer when you try to think of everything logically! I fairly routinely scan the laptop as a whole and make a point of keeping most things up to date in the world of the OS and VP, although I suppose you can never be overly secure!

For people who do not have a second computer, sometimes a stand-alone recorder such as an H4n can be an attractive solution.

if I change to - default sample format from 32 bit float to 24 bit would it help?
I am recording guitar on a droom groove and it’s off tune and also to slow when guitar recorded.

No. 16-bits is generally better than human hearing. If you are recording from analog/hardware you are limited to the resolution of your analog-to-digital converter.

And by default, Audacity automatically converts everything to 32-bit float when you record. …Same when you open a file, by default Audacity will convert to 32-bit float for editing-processing.

Being off-tune and too slow probably means there’s a sample rate mismatch somewhere. For example, if you’re recording at 48 kHz but Audacity thinks it’s 44.1 kHz (both are very common sample rates), it’ll play back slightly slow and almost 1.5 semitones low which definitely will sound flat.