When preparing an audio track, there's much to consider. How clear does it have to sound? What kind of audio is it—a speech, an orchestra, a sound effect? Each of these has a minimum quality requirement.
- Spoken tracks, like podcasts and narrations, need to be clear enough to understand the speaker and prevent distortions that could be distracting.
- A music file usually has many intricacies. Its main purpose is to have an appealing sound, so quality should be as high as possible for maximum enjoyment.
- A sound effect is usually short and for decoration, so quality isn't a big concern.
The quality of an audio track is affected by multiple settings. Three of the major ones to pay attention to are bitrate, sample rate, and channels. Click through the tabs below to learn more about each of these settings.
This setting is basically "the rate of bits," or how much data is processed in a given amount of time. Bitrate is most commonly measured in kbps, or kilobits per second.
For Example: There are 8 bits in a byte. If your bitrate is 320kbps, it means that your file size is 320 kilobits (or 40 kilobytes) for every second of audio.
If the bitrate is set too low, the sound may become distorted, and more subtle parts of the audio may be lost. Most basic web audio is set between 125-320kbps.
The sample rate for audio is typically kept at 44.1kHz (kilohertz), or 44100Hz (hertz). This captures the range of audio perceptible by human hearing, so it's acceptable for almost any audio use. 22050Hz (half of 44.1kHz) can be used by low quality mp3s.
The channels of an audio file measure how many separate tracks are recorded to be assigned to one or more speakers. Different numbers of channels are used for different listening experiences. Mono produces sound from one speaker while stereo is used for two speakers. Beyond that are surround sound setups (5.1, 6.1, 7.1). As you might expect, the fewer channels you have, the lower the file size. For website audio, you should only ever need stereo at most. For music, stereo will almost always be preferred. But for purely spoken audio, mono may be acceptable.
Remember, before making any changes to an audio file's setting, or compressing its quality, be sure you've kept your best version available as a copy! You can always lower quality, but once that data's gone, you can't get it back. Having the original will let you start over if you end up unhappy with the result.
