Recording Audio

Getting Audio "in" to the computer

There are a number of ways you can get audio onto, or into, a computer. Two of the most common would be recording audio directly into your computer, or using a digital audio recorder and then transferring the files to the computer after they're recorded.

To record audio directly to your computer you need to see if you have an "audio-in" port or jack. Look on the front and back of your computer, it might be designated by the word "mic" or with an icon of a microphone, and typically is a mini-jack (like what you'd expect to plug headphones into). If you have one then you can plug a microphone into it - which you can purchase at most computer or electonics stores, and record your audio.

If you don't have an "audio-in" option on your computer, or you simply prefer not to record it there, you could also record your audio into a digital recorder and then transfer it to the computer (usually with a usb cable). Since it's not possible to enhance the quality of a recording, be sure to get a recorder that records decent quality audio, even if the file type isn't exactly what you'll want in the end. It's possible to convert a file from one format to another.

Applications

There are a number of applications that will allow you to record audio directly into your computer, as well as convert audio you've transfered to the computer from another device.

If you do not have a program that will save/export audio files as mp3s we recommend Audacity. It's a free, cross-platform, and a wonderfully easy to use application. It will let you record, edit and save your audio as an mp3.

The ultimate constraint, with regard to podcasting, is that you need to be able to export the audio into a format that will be useable by your intended audience... the best bet, therefore, is an mp3. This is because iPods, mp3 players, and computers all will play a standard MP3 with little to no additional software needed.

Environment

Where you record your audio is just as important as the content itself. Some situations can't be helped, but if at all possible you should be sure you're in a quite room with a decent quality microphone attached to your computer (or audio recorder). If you're in a noisy place you might consider using a lavaliere mic, or some other means of focusing on your voice and not the other noises that might be going on around you.

Quality

There are quality settings to audio recordings, just like the resolution of an image. And just like an image, there are different kinds of settings... they include the following:

Sample Rate

Generally speaking this is the number of units the recording is broken into. To liken it to images again, it's like setting the number of pixels in an image. You set the number of samples (of the music) that are recorded each second. This, in turn, allows for a certain number of frequencies to be reproduced by the digital sound. The more samples you have, the higher the frequency you can produce. Commonly used rates are:

Sample Rate	Description
44.1 kHz	CD Quality - able to produce frequencies that span full range of human hearing.
22.050 kHz	1/2 CD Quality - great for speechs and some music, or a mix of the two (not fully quality but perfectly adequate for many purposes).
11.025 kHz	OK for voice, some noticable "digital" sounding effects.
8 kHz	"telephone quality" - again, OK for voice, but sound may be somewhat muffled.

Sample Format (16 or 32 bit in Audacity)

It's a setting the dictates how the samples get written as a file. 16 bit is CD quality, but 32 bit is more flexible. The recommendation is to record at 32 bit (as long as you have the space on your computer) and then save a version out at the lower quality.

Stereo vs. Mono

Stereo and mono are options you may have when you record audio. The inclination would be to choose stereo, since we all think that sounds better. But mono will still play through both speakers, it'll just be the exact same sound. In truth mono might sound a slightly muffled, but it's hard to notice unless it's pointed out, or you're an audio engineer (grin).

Anything that is CD quality or higher will more than likely be adding nothing more than file size to your podcast. CD quality audio is 44kHz, 16bit, stereo sound (in some applications all your given is a bit rate, 192kbps would be about CD quality audio). In most cases you can get away with sound that's about half that quality and still hear little to no difference. The best rule of thumb is to test a few quality settings by exporting them and listening to your audio... shoot for the lowest file size you can get without sacrificing more quality than you, and your audience, can live without.