Submit Hint Search The Forums LinksStatsPollsHeadlinesRSS
14,000 hints and counting!

Change the pitch of recordings with AU Lab Apps
Tiger only hintOne of the questions asked on my previous hint about playing podcasts back at 1.5x speed was how to change the pitch. If you have the Developer Tools installed (a free download after registration, or from the 10.4 installer disk as an optional install), you have the very-fun-to-play-with AU Lab application -- you'll find it in /Developer -> Applications -> Audio. And with AU Lab, you can pitch-bend (very smoothly, too).

First, open AU Lab, which creates a default document. Hit Return on the first dialog box, asking about default inputs and outputs. Next, you'll need to add an AUAudioUnitGenerator from the menus, or hit Command-Shift-G. The type is AUAudioFilePlayer, and hit OK. This creates something that can play sound files (like MP3s) into the Audio Panel that you're creating.

When you created the audio file player, a new window appeared to configure the player. The upper area is where you select what file or files to play. Click on the "+..." area (sorry, it's not a very standard GUI, and took me a while to figure out), and select a sound file, which will be added to the list. Keep that window open, because you'll need to hit the big Play button near the bottom soon. In fact, you might want to hit play, Pause, and Rewind to make sure you have the right sound file.

Now it's time to add the effect. On the AU Generator panel (leftmost, probably labeled Track 1), go to the "effects" area and click on the uppermost downarrow, and select "Apple... AUPitch." This attaches a pitch bender to the output of the file player! The dialog box is worth playing with just for fun, so hit the play button on the AUAudioFilePlayer window, and play with the knobs on the AUPitch controller. "1200 cents" is a perfect octave, so to make a singer sing along with himself as a chipmunk, set the numbers to "1200, 50%, 50%, 50%," from top to bottom.

Once you're satisfied with the pitch change that you want, it's time to record it. In AU Lab's Preferences, select the recording subtab, and for easy import into iTunes (for MP3 conversion), select 24-bit AIFF as the format, and adjust the file save options as you wish (I put mine on the desktop for easy access). Close the preferences box when you're set.

Now for the tricky part. Note the location of the REC tab at the bottom right corner of the "Master Out" Audio strip. You're going to want to hit that immediately after or perhaps immediately before pressing Play in the AUAudioFilePlayer window, so get them positioned very close, and do it!

When the track is finished, toggle the recording back off. You're done! You've made the sound file.

If you double-click on the sound file, iTunes should import it and play it just fine. However, it's huge. To make it an MP3, select it in any library view, and use the iTunes menu "Convert Selection to MP3," which uses your current "ripping" settings. (I haven't tried this, but I think you can set the start and end points if you want to trim some excess dead air.) When you are happy with the MP3, you can delete the AIFF file.

When you are done playing with pitch, another great effect is the "AUMatrixReverb," which has presets that can make your sound appear to have been recorded in a huge room, for example. Enjoy!
    •    
  • Currently 3.67 / 5
  You rated: 5 / 5 (6 votes cast)
 
[16,138 views]  

Change the pitch of recordings with AU Lab | 7 comments | Create New Account
Click here to return to the 'Change the pitch of recordings with AU Lab' hint
The following comments are owned by whoever posted them. This site is not responsible for what they say.
Change the pitch of recordings with AU Lab
Authored by: Macoman on Jan 11, '06 12:40:42PM

Or You could just open the audiofile in Quictime, hit Command+K (or use the menu, your choice...) and choose the pitch you like.

Works with movies as well as audiofiles.



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: merlyn on Jan 11, '06 02:02:16PM

Command K has "speed", but that doesn't change the pitch. That's the reason people asked on the previous thread about how to change the pitch.



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: gregpare on Jan 11, '06 02:38:55PM

Nice -- thanks.



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: blgrace on Jan 11, '06 03:59:15PM

You could also use GarageBand's Vocal Transformer effect.
Import the audio into Garageband, <cmd> i to bring up the tracks effect settings and select Vocal transformer from one of the effects slots and change the pitch.



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: ocdinsomniac on Jan 12, '06 02:09:44PM

You can also set a recording delay in the Recording Preferences, so that when you hit record you have a few seconds to hit play on the sound file.

Also, this records dynamic changes to the sound file, so this can be used to record pitch changes (or speed changes, using the AUVarispeed effect) on the fly.

Super-cool hint! thanks!

-systemsboy



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: merlyn on Jan 12, '06 06:27:09PM

There goes another hour. I didn't even notice AUVarispeed or AUTimePitch on the file playback unit! Wow!



[ Reply to This | # ]
Change the pitch of recordings with AU Lab
Authored by: CraigMarston on May 13, '10 08:03:31AM

This is a great tip, thanks!

I did find it a little tricky, but only because like you said, the interface is a little unusual.



[ Reply to This | # ]