hpr-knowledge-base/hpr_transcripts/hpr1404.txt

Episode: 1404
Title: HPR1404: Editing pre-recorded audio in Audacity
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr1404/hpr1404.mp3
Transcribed: 2025-10-18 00:54:54

---

It's Thursday the 19th of December 2013. This is Hacker Public Radio episode 1404.
Hi everybody, my name is Ken Fallon and you're listening to HPR 1404 for Thursday the 19th of December 2013.
Today's show is editing pre-recorded audio and audacity. You can find a supporting screencast
along with this video in the show notes. For this show, I'm going to assume that you record your show or interviews externally with another device.
That might be a in the mumble room where you've recorded a group meeting and you've got a WAV file.
It might also be a dial-in session that has come in via a dial-in or via a recorded record or Skype call recorder.
Or even on an external device like the one I'm using right here which is a Zoom H2 audio device.
I also use Sansa Tlipp or my mobile phone or indeed the audio track from a simple video recorder.
However, you get the audio. We're assuming that you have a WAV file associated with the audio or a WAV MP3 or whatever associated with the audio that you're going to bring into your computer.
And we're going to assume that audacity can open it.
Regardless of the device, a general rule of thumb is just try and get the best possible audio quality.
So if you've got an compressed audio option, for example WAV or FLAC, then you should choose that and then set all the settings to the highest possible values.
And that should leave you in a good way to be able to record to edit your shown good quality.
Regardless of what you have, send us what you have and we will put it out here where we will never reject audio for audio quality as long as it's audible.
If this is your first Hacker Public Radio episode or if you come across this video online, Hacker Public Radio is a community podcast network where they host our people in the community.
We take our shows from the listeners themselves and that's right folks. If you listen to Hacker Public Radio, we would like to hear a show from you.
Lots of people find how they got into technology, introduction to Linux or introduction to podcasting or whatever.
There's a list of requested topics on the website as well as more information on how you can record a show.
So without further ado, we're going to assume you have installed audacity as well.
If you are running a W&B system, you can get appget, space install audacity or YUM space install audacity if you're on Fedora.
There are binaries available for Windows and for Mac OS X on the audacity website.
So assume also your audio file is installed.
When you open all audacity, you get a nice window, a fairly Spartan, to be honest, title bar audacity and a file, edit view, etc. help menu.
On the top, underneath that is the typical controls for CD player polls, play, stop, go to the start, go to the end, record, which we're not going to be using.
Then we have the tool bar menu, selection tool, envelope tool, draw tool, zoom, time shift, and the multi tool, please select that one if you haven't already.
It's shaped like an asterisk and it encompasses all the other tools into one and it really is quite simple.
The only other tools that we're going to be using, buttons that we're going to be using are the zoom buttons here at the top right hand corner.
It's shaped like a magnifying glass, zoom in, zoom out, fit selection and fit project.
We won't be doing a lot with the edit or the other menus, but we will come across them from time to time.
Before you do anything else, I'd like to point out that at the bottom right hand corner there is a project rate, sample rate in Hertz.
If that's not already set to 44, 100, then can you please do so.
That will set the rate, that's when you export a file, that regardless of what you bring in to audacity, be it from your phone, which might have a lot lower sample rate, that it will export it with this higher sample rate or it will bring higher down to lower.
This is a nice average that we use here in HPR.
The first thing we want you to do is open your episode and you can do that by selecting file, open, and you browse to the location of your episode.
This happens to be my one here, it's a well file and I just press open.
I'm right there, it imports the audio without any issue.
What you'll see is, depending on the audio, whether it's a stereo track, and you can see on this one that it is stereo because, open the top right hand corner, it says, stereo.
And it's got two tracks, a grey area, lighter grey area, a blue line in the middle, then second track, exactly the same thing.
Now, on HPR, it's mostly an audio only, it's an audio podcast of people speaking, so it's not really necessary to have two audio tracks.
If you're doing something like an oral audio, or you're doing sample rates or experimenting with audio formats, or experimenting with the left and right audio,
we will absolutely support that, but please make note of that in the show notes as you're uploading so that we don't automatically convert it to a single track audio on the server side.
No harm to drop admin at Hacker Public Radio Align either, as well, just so that we know what's going on.
Right now, the first thing I'm going to do is I'm going to convert this from two tracks down to a single track.
And how I do that is I go to the tracks menu, and the second option is stereo track two mono.
If you click that, then it will convert the entire thing, the left and right here, compress them down into one, and that has the effect of making the audio, audio file a lot smaller.
One thing that you'll notice in the video if you're watching is that the Zoom H2, and this is particular to this audio recorder, that the track itself is really, really quiet.
So if I select anywhere here and press the play green triangle, you'll notice that it's very, very quiet. You hardly hear anything.
As I'm playing that, I can barely hear it myself. You can see the left and right lines, tracks moving in and out as it's playing.
So what I want to do here is amplify the entire audio. So the best way to do that is simply go into the effects menu, and the menu bar, and second one down again, press amplify.
And then we get various different options of which you're not going to do anything with, just press OK, and let audacity do its thing.
It will take the highest peak and bring that up so that it just doesn't clip.
And if you've got a really good recorder like the Zoom H2 is, everything comes up very nice and neatly.
So now we see lots of peaks and throughs in our track, and it's all quite squashed together.
The track is 44-41 minutes here.
What I like to do at this point is tron case, clip off the front and the end section of the podcast.
I don't do any other editing other than that, but I will show you how to do it.
Simply because I don't think there's any point, that's just my style. I prefer people to unhp or people are very forgiving.
And if there's a few on the nose, then that's fine and that's acceptable as proven by me.
So it is absolutely fine to have that in here.
But what I do want to do is tron case, show you how to tron case the front and the end.
Because there's usually a bit of additional audio there that you don't really want to come out.
So say, for example, as you're pressing, putting the microphone onto the table or you're muffling with people's tools.
You might get that sort of thing at the beginning and the end of the audio and you want to trim that out.
Another reason that I want to trim my recordings of interviews is that at the beginning of each interview,
before I do the interview, I ask the person to phonetically speak out their email address and to speak out their website and their name.
So with those three pieces of information, I can just listen to Wav01020304 and know that Wav0104 is played.
And I hear, yes, your name is JoeBlog, example.com and your email is Joeat, example.com.
So that makes it very easy to identify, but obviously you don't want that in the interview itself.
So as a record, I get that information, then I go 1, 2, 3, a little bit of a pause, and then I start speaking.
But right now, because the interview that I'm doing is on the Zoom H2, it's relatively quiet.
It doesn't pick up a lot of that stuff, but I'm just going to show you how to do this.
So I click at around 1 minute mark, click and drag to the 0, and then I go up to my 4 magnifying glasses, and I click the third one from the end, which is fit selection.
And that then assumes in on that area.
So instead of being from 0 to 41, it's now 0 to 105.
So I've zoomed in on about 1 minute of it, and you can notice that there are different spaces and pieces, bits of silence.
And it writes about 35 seconds in, there's a peak here, so that possibly could have been a gnome or a gnome.
And as you go through the audio, if you are editing your own audio, you start to notice the shapes of the ooms and the ooms.
So I'm just going to click before that peak there and press play and see exactly what it is.
So it's nothing more than me going, I, so what you could do is you could click and drag, so clicking behind it and dragging to the front, clicking in front and dragging to the end.
So let's listen to that piece of audio now before I delete it, and then I'll delete it and then we'll listen to the audio afterwards.
So what I could do then is highlight that entire area and delete the eye and then selecting before the same selection again and now play it without the eye, without the eye having deleted it.
So this bash script like to keep abreast, so the eye is completely gone.
If you want to do that, that's fine, but I don't, so I'm going to go edit and undo delete, and then here comes my eye is back in again.
So that is how you would edit your file, but your file is quite large, so you might have quite a lot of those.
What I suggest you do if you are doing that is then save this as a project, so file, save project as, and then save it as something.
I'm not going to do that because I don't, this is a temporary edit that I'm not going to destroy the source audio, so I have that.
So what I want to do really is click, eliminate the first click as I turn on the audio, so I'll highlight just before it starts to speak, drag to the zero seconds and press delete on the keyboard.
I could also do edit, remove audio, cause our delete, but I'm not going to bother.
Down on the bottom, there is a scroll bar from left to right, I could scroll the whole way over to the end, which I've just done now, and at the end I highlight a few seconds before the end and I press play.
It's a little more eccentric than normal, and there's nothing really wrong with the ending of that, and I'm going to click a little piece just for the sake and delete it.
So now I'm going to highlight, sorry, not highlight, fit the entire project, going up to my magnifying glasses, selecting one on the extreme right, and then I'm zooming on my entire audio.
So my audio is now edited, and as you can see, the audio is 41 seconds long.
As you're recording a show, very often you might want to look something up or confirm a fact or a cough of microphone.
So quite often what I do, you can train yourself to do this, is just be quiet, don't speak, try and make as little as noise as possible, and then there's very little audio recorded by your device.
So what you can do then afterwards, at this point, is truncate that silence.
So if you're going to effects in the menu bar, and press truncate silence, and again we're accepting the default, so dust is pretty good at this, so leave it up to do what it's going to do.
And it's now truncating the silence, so from a little over 41 minutes, it takes it down to just over 37 minutes, so that makes very nice, tidy audio file.
So that's pretty good.
The next thing we want to do now, you can upload your file like this, but it's also nice to edit the intro and outro if you wish to do that.
So we'll do a little bit of overlap.
So the thing I'm going to do is file import audio, and here we have the intro.flack file, which I've downloaded from the website.
I have a public radio.org website, and I'll just import that there.
And you see that the audio has been put at zero seconds, just like the start of the show itself, that's not really what I want.
So what I'm going to do, just to let you hear that, I'm going to press the home button to move the play line to zero, and I'm going to press the play button, just one second, so you can hear what's going to happen.
So you hear that there, that the talking and the show are going on at the same time.
So I'm just going to highlight about a minute in, highlight the whole section, and then go up to my magnifying glasses again.
And this time take the second one in from the right over, sorry, up on the top right, second one in.
And now, now we are exposing the audio that we can see the throughs again.
And what we'll do is we just click on the top track, though, it is the podcast one.
And you can see that the intro track plays, and you can actually see the repeating pattern of the tune, you can really see the repeating patterning, and then the crescendo at the end, and then the taper off as a taper's off.
So what I like to do is have my, just as it begins to take off, taper off, I have the hello everybody, my name is, and then edit that in.
So what I'm going to do now is highlight the first track, press control key, and the cursor goes from a selection cursor to your traditional eye, Roman numeral eye to a move left and right arrow.
So if I click and drag, click and drag the audio track to about 30 seconds in, and that's just actually the sweet spot where the crescendo is finished, and we're starting to play.
So I'm positioning the track play track at about 25 seconds, and let you hear what that sounds like.
So there you go. That is the positioning of the intro relative to the outro. I don't tend to do that with the outro, such because when I finish, and then I like to have a nice tidy end end where the outro comes in just as a, as I say, tune in tomorrow for another exciting episode, a hacker public radio.
So what I will do is I will press the project button again, and then I will go file import audio, and this time the outro, which again is available from the website, and that will put it down at the zero.
I'll go down to the outro, and I'll click hold down the control, and I can drag this over.
So I'll drag it over to the end, and because it's zoomed out the entire project, I need a little bit of space, so I'm just going to go down to the scroll bars, click on a scroll bar and scroll to the right for a second.
So that gives me space to position the outro over and back.
So now I'm looking at between 8 minutes, the podcast ends at about 37 minutes, and I've got a few minutes of free space up until 45 minutes.
So I'm going to click on the outro, and I'm going to slowly drag it over, and as I do, you'll see a yellow line appears when the ends of the outro and the ends of the show line up, but that's not what I want.
I want the beginning of the outro to be the end of the show, and that's that done. It's done.
So I've now edited my podcast. Now will be a good time to save, especially when you work on multi tracks, audacity tends to get very flaky.
It's very good at recovering, but it does get a bit flaky.
Again, before we do anything now, we just confirm that our project created a set of 44100, and we go file, export.
And I like to just tag on something here at the end, so there's no fear that it's overriding, and I have my podcast name, the best YouTube downloader script is what it's called now, and I'm just going to tag on dash edited to the end.
And right down here, various different formats that yours might not look like this. You mean you might not have MP3 support, but either select WAV, which is WAV, Microsoft Signed 16-bit PCM,
pulls code modulation, or in our case, what we're looking for is flak files. And on all of these you can select options.
So here this would normally be set at five, under level flak export setup, level five, now we select level eight, the best.
And then this would normally be set as big depth of 16, we're going to switch that to 24 bits, and we're going to press OK.
So there we are, we're now going to save the file name with a flak, we've set our options, we're going to press save, and here comes up the metadata tags that you can enter for your show.
I have some of them pre-populated here because you can save them as a template or load a template, and then you can press the default button.
The artist name in my case is Ken Fallon, and the track title is the track title for this.
This is the best of you.com, down, stripped.
And the album is Hacker Public Radio, and the track number, because I don't know I could look it up, I could pick up a track number if you wish.
So whether you do that or not, that's not really important. And then the only thing you need to do now is press OK, and it will export the entire project as a flak file.
So that can take some time.
Other than that, that's pretty much it, you can then email admin at Hacker Public Radio or go on to August Planet at freenode.com.
And you can get yourself the username and password for the FTP site, and then upload your show.
I would ask that you fill in your show notes correctly, and read the readme file every time that you upload if there's been a period of time between uploading a show.
That you could reread the readme file, because that really helps us a lot, especially the top elements where it tells us if you've added the intro and outro, there's really no way of us identifying whether that is because some people put it halfway through and put things at the end.
So really helps us if you put that in. You can also specify a date that you want your show to be aired on if it's a special date, or if there's a lot of people in the queue, you can leave a few spaces for other people to add shows after you.
So that was it. I hope you found this enjoyable. I hope you will consider recording a show for HPR. It's not that difficult. And just by the way, if all that was too much for you, it's very, very easy just to
email admin at hackerpublicradio.org and we'll do all this for you. Believe me, this is taking a lot longer to do than it would normally it, it becomes second nature to you after all.
With that, I'll sign off and tune in tomorrow for another exciting episode of Hacker Public Radio.
You have been listening to Hacker Public Radio at hackerpublicradio.org. We are a community podcast network that releases shows every weekday Monday through Friday.
Today's show, like all our shows, was contributed by a HPR listener like yourself. If you ever consider recording a podcast, then visit our website to find out how easy it really is.
Hacker Public Radio was founded by the digital dog pound and the economical computer club. HPR is funded by the binary revolution at binref.com, all binref projects are crowd-responsive by linear pages.
From shared hosting to custom private clouds, go to lunarpages.com for all your hosting needs.
Unless otherwise stasis, today's show is released under a creative comments, attribution, share a line, lead us our license.