Bit Depth Vs. Bit Rate in Audio Recording

One measures speed. Both indicate quality.

If you hear the digital audio terms bit depth and bit rate, you might think that these two similar sounding expressions mean exactly the same thing. It is easy to confuse the two because they both begin with "bit." However, they are two completely different beasts.

Bit Rate in Audio Recording

Bit rate is a measurement expressed in kilobits per second, which is thousands of bits per second. Kbps is a measure of bandwidth of data transmission equipment.

It indicates the amount of data that flows in a given time across a digital network.

For example, a recording with a 320 kbps bit rate is processed at 320,000 bits per second.

In general, a high bit rate recording delivers better quality audio and takes up more space on your computer or mobile device. However, unless you have high-quality headphones or speakers, you aren't likely to notice the improved quality over one of a lower quality. If you are listening over a standard pair of earbuds, for example, you aren't likely to notice the difference between a 128 kbps file and a 320 kbps file.

Bit Depth

At first, bit depth might seem a complicated subject, but in its simplest form it is just a measure of how precisely a sound is represented in digital audio—the higher the bit depth, the more accurate the digital sound. You have probably already encountered songs that come at a certain bit rate—either via MP3 download services or streaming music sites—but rarely is much said about bit depth.

So, why bother to understand bit depth?

If you are going to digitize your collection of vinyl records or analog tapes in order to store them as high-quality digital audio files, then you need to know about bit depth. A higher bit depth gives a more detailed sound recording. A low bit depth causes quiet sounds to be lost.

This attribute influences how much detail you capture from the original analog recordings. Getting the bit depth right is also critical for keeping background signal interference at a minimum.

For more information on bit depth, read  Bit Depth Definition and Description.

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