To Clean or Not to Clean
One of the things you'll notice about your recordings is that they aren't perfect. Sometimes the problems are so bad that the only real option is to re-record a particular track, but more often there will just be some misplaced words, stray sounds, or odd background noises on the recording. The question is, what do you do about it?
The first decision is philosophical: Should you do anything to the file at all? There are podcasters who feel that one of the charms of the medium is that you hear dedicated amateurs creating audio programs, and that it's best to hear them "warts and all." This is a
valid point of view for many podcasts, and it
your production process. If your podcast must answer to no one but you, and you like the idea of the "raw" podcast, then you can skip on to the
section. If, on the other hand, you need to know how to recover from
problems, let's look at some options.
Cut It Out
The first technique that you can use is to simply edit the offending sound out of the track. This is
if the sound is very short and louder than the other sound at that moment. Figure 8.14 shows a sound like thisthe result of someone
Figure 8.14. A spike is a very brief, sharp sound.
Now, we listen to the track to hear what's going on behind the thump. If it's a vowel sound in the middle or at the end of a word, then we're probably OK just editing it out. If it's during a hard consonant ("K" or "T", for example), it's going to be much harder to clip the thump without making the word sound rather odd. In this case, we were lucky, and the edited track with the pop removed can be seen in Figure 8.15.
Figure 8.15. A short spike can often be removed without any effect on the
Filters for Clarity
If just editing the offending sound out isn't an option, there are a number of different filters and processors you can try. Your podcasting software may come with some built-in, and there are many available free or at very low cost on the Internet. Let's look at some of the possibilities:
EqualizerAn equalizer breaks the sound spectrum up into separate bands, and allows you to control the volume of each
separately. If you have an annoying, constant noise that's at a specific pitch (from machinery, for example), you can use an equalizer to "
" the particular frequency of the sound and eliminate the noise. This is most effective if the noise is not in one of the bands that is shared by the human voice.
Noise FilterA noise filter takes advantage of the fact that the voice that you're recording tends to be the loudest thing on the track. Many noise filters work by eliminating any sound that doesn't reach a certain volume. This type of filter is commonly referred to as a noise gate. With these, when you're not talking, nothing is being recorded, though time will pass so that the flow of the recording sounds natural. These can be very effective at eliminating low background noises, but you should be aware that the "room noise" will be recorded when you're talking, but not when you're silent, leading to a very unusual sounding recording. There are times when it's the only way to get a usable track, but be sure to try it before using this filter for anything critical.
CompressorUsing a compression filter can reduce many sounds that lie just outside the volume and spectrum of the voice you're recording. This will also change the sound of the voice, though you might like the result. If you re-expand the recording in a
step, much of the noise can be left behind, while the voices return to something closer to the original sound. Many of the voices in the commercial songs you hear have been through this compression/expansion process, but making it work can be a complex process that requires a lot of listening and experimentation.
No matter which filter or process you decide to try, there is
no substitute for listening and experimentation. After looking at, and listening to, the possibilities, you might end up looking anew at the "raw" option, and that's just fine.