Digital Audio (Lesson 3) - Posted on 2017-11-09 by Hunter Rick

Today my mentor went over digital audio and the technical aspects behind it. 

He mentioned how:

Sample Rate - is the amount of samples taken of a sound within a single second to increase the accuracy of the sounds replication in a digital format. It must be double the amount of the frequency range of your recording in order to accurately replicate all frequencies, however a standard 44.1Khz is used instead of 40khz because there is a gradual roll off involved and there must be headroom given as to not effect the higher frequencies.

Bitrate - is how much dynamic headroom is available to a waveform.

Quantization Errors - is when an error is made in the recreation of the sound. This is unavoidable, but the higher the bitrate, the less chance of this happening to each individual sample. When quantization errors do appear they create white noise in the digital version of the recording that was not present in the original.

Clipping -  is when a signal reaches an amplitude above the bitrates available "ceiling" or limit and so the data is compressed and flattened into a square shape, giving it a harsh digital distorted noise that is usually unintended.

We also went over the many different audio formats that have changed over the years such as CD's, VInyl, and tape decks all with their own advantages and disadvantages. With CD's your audio becomes much higher quality, but quantization errors and appear and some say it ends up revealing sounds in the mix that are unwanted. Vinyl and Tape deck tend to be noisier and less faithful recreations as well as more limited in space, but hide smaller possibly unwanted details like the sounds of strings being plucked.