Digitising Sound

• Recording quality improves:

• the more accurately we record the wave height

• Increasing the sampling rate (frequency) means recording more data points

• Increasing the bit-rate improves the accuracy of each data point

Lossy Compression

Removes sounds that we can’t easily hear or that least affect the perceived playback quality.

Leaves out some data from the original file, so the output can lose some sound quality.

Lossless Compression

Lossless compression formats are able to reduce the file size when compressed but do not lose any information.

File Formats

• WAV and AIFF files are uncompressed audio files

• Lossy file formats are still very popular as they reduce the file size well

• MP3 (MPEG-1 Audio Layer III)

• AAC (Advanced Audio Coding) – typically higher quality than MP3