Sunday, September 16, 2012

How to join audio tracks smoothly in Audacity

Audio tracks can be mixed easily in full fledged video editors like kdenlive or Adobe Premiere but for mixing or joining audio they would not provide the amount of control that audio editors like Audacity provide. The example I am going to show today would demonstrate the range of tools in Audacity that allows us to control the waveform and to mold it to our desire.

Today I am going to take a small track like a small 1 min. clip of storm sound and make a long continuous sounding storm audio clip from it.

STEP 1 : Open file

Open the clip in Audacity.

STEP 2 : Removing unwanted audio portion

There is always unwanted sections of the audio that we have to discard. Select the portion of background noise or unwanted audio.

Press DELETE key.

STEP 3 : Duplicating the track

Now we make a copy of the entire waveform and paste it at the end of the track.

Select the SELECT tool (the one which looks like I). Then select the whole waveform and prss Ctrl+c. Now click approximately at the end of the track and press Ctrl+v to paste.

STEP 4 : Editing the intersection

The pasted waveform would not exactly match at their ends. To remedy this we have to zoom into the intersection.

Again select the intersection.

Them select the ZOOM tool just below the SELECT tool and click on the waveform couple of times so that it looks like this.

STEP 5 : Removing intervening blank space

SELECT the intervening blank space and DELETE it.

ZOOM some more and DELETE some more of the blank space.

We would end up with something like this.

Here notice that there is a discontinuity (where I have put the marker). This causes the audio to change sharply and it would be noticeable to the listener as a cut and paste job. We have to smooth this part out.

STEP 6 : Editing the waveform

Now select the tool that looks like a pencil (it is called the DRAW tool). Using this tool we can draw points on the waveform. Use it to smooth out the intersection of the tracks. It  should look smooth as this.

STEP 7: Fix the ends

We now zoom out using the ZOOM tool by pressing the  Shift key while clicking on the waveform.

Go to either end.

ZOOM in. Select the DRAW tool again. And draw the waveform such that it begins from zero and ends at zero values. Normally most audio clips begin with zero values but if it is cut from a bigger clip then the cut-out clip might start from a non-zero value. Smooth it out just as in the previous step.

STEP 8: Export to MP3

Select File -> Export and give the extension .mp3 .

Save file would just save the audacity project and it would not create a sound file.

DONE !!!


1 comment:

Donal Sampath said...

Thanx i really appreciate this.. u save my day.. because i have a special project to do

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