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View Full Version : How can I speed up audio, without changing the pitch?



ironpony
09-09-2017, 02:57 PM
Basically for an effect I want to do a short film, I want to be able speed up a shot of someone talking so it looks like they are talking in fast motion. Now in Premiere Pro, there is a tool that allows you to do this called the rate stretch tool. When I apply it to the video to speed it up, what it does is, is that it removes frames from the video to speed it up into fast looking motion.

However, with audio, the rate stretch tool doesn't seem to do that. Instead of removing frames in audio (or samples I guess they are called in this case), what the rate stretch tool does it, is, is speed up the audio and changes it to a higher pitch. This makes the actors voice sound much higher, which I don't want to do. I want the actor to talk really fast, but not in a high pitch and just have samples removed, the same way frames are removed in the video, without any pitch changing.

Is this possible to do in premiere pro?

Studio Nine
09-11-2017, 08:04 AM
What you're looking to do is called "formant preservation". Not a mis-type the word is "formant". So if your software has to ability to preserve formant in the audio while stretching the video, that's what you're looking to enable.

ironpony
09-30-2017, 01:04 PM
Okay thanks. I have it where the pitch is not changed whole the person is talking very fast. However, now there are several popping sounds when the person speaks fast.

I think it's because when you remove a lot of samples, it creates popping sounds in between i am guessing. Is there a way to get rid of that after?

Walter B
10-01-2017, 06:32 AM
Samples are not removed in de the audio.
The speed up just created some radical waveforms.
Export that audio and clean it up.

What version of Premiere are you working in now, since for many years when you speed up sound it comes with a little box where you can choose to not pitch the sound.
So you are either:
- blind
- using a prehistoric version
- asking BEFORE even trying.

ironpony
10-01-2017, 10:22 AM
I am using Premiere Pro CS5.5. It has the box where you can select not to change the pitch, while speeding up the audio. But then it has all these popping sounds, from removed samples though. I tried that and got the popping sounds all over.

I also tried speeding it up, with the pitch changing, then trying to change the pitch back to normal after it was sped up, but could not change the pitch back. Basically Premiere Pro will only allow me to change the pitch by -12 semitones, where as I would need a lot more to change it back I am guessing?

Walter B
10-02-2017, 07:39 AM
I've been speeding up and slowing down sounds like forever. No samples are being removed. The wave gets compressed in time and reinterpreted on 48kHz. That can cause popping, because you can get abrupt changes in the waveform.
Listen:
export the popping sound and heal it in Audition.

I usually had 1 or 2 pops in sped up sound.
I guess your speed up is quite extreme.

ironpony
10-02-2017, 08:50 AM
Oh okay I see. Well since I am speeding up a lot of dialogue, I got like 2000 popping sounds.

Walter B
10-03-2017, 09:56 AM
Why did you edit your post to remove vital information?
You want more people to waste time on guessing what could be the problem?

You wrote:
"Oh okay I see. Well since I am speeding up five minutes of dialogue into about 10 seconds, for the effect I want, I am getting like 2000 popping sounds."

That is 6000% speed. 60 Times faster than the original.
You know why a waveform is called a waveform?
Yes, because it is a wave.
Making a slope 60 times shorter makes the slope steeper. Many sounds already have a steep slope: that is why it pops.

Why is it you never edit to add info, but only to subtract info from your posts, while you should know by now you always give too little information for people to help you quickly?

ironpony
10-03-2017, 10:44 AM
Oh sorry, I didn't mean to remove vital information. Basically I removed it cause it wasn't five minutes exactly, and I thought it would lead to miscalculation if I rounded it up to five minutes.

So if I want to speed up audio by that much, and not having popping sounds, than what do I do? Or I could live with the popping sounds, if they are okay, and still pleasant on the ear, and theater speakers.

Walter B
10-03-2017, 12:15 PM
Just learn to read: it is in the previous replies: use Audition to fix it.

phVIDEO
05-27-2018, 10:34 AM
make cuts?

ironpony
05-27-2018, 02:27 PM
But that would be thousands of cuts to make, plus it would create poppings sounds, if there area cuts.