Audio Quality based on Sample Rate and Bit Rate
July 1, 2009
Sampling rate refers to sound frequency range, from 8,000 to 96,000. Usually 8,000 is selected for audio recording, 44,100 is for CD recording, and 96,000 is for film theater recording.
The higher sampling rate the file is, the wider the frequency range is. Highs will be higher, lows will be lower; higher is better quality. You won’t notice the differences on lower quality headphones or speakers. The quality difference will be noticeable in high quality headphones and speakers.
Bit rate refers to how many “bits” of space the file takes per sec of audio. The higher the bit rate, the higher quality the audio is.
Of course high sampling rates and high bit rates would give the best quality. However sampling rates do not affect file size as much as bit rates.
When you save audio in wave you will be selecting audio quality based on sample types. WHen you save audio in mp3, your audio quality is based on bitrate.
Sample Rates:
- 8,000
- 11,025
- 16,000
- 22,050
- 32,000
- 44,100
- 48,000
- 88,200
- 96,000
Sample Types:
- 8 bit
- 16 bit
- 24 bit
- 32 bit
- 32 bit float
Bitrates:
- 16 kbps
- 18 kbps
- 20 kbps
- 24 kbps
- 32 kbps
- 40 kbps
- 48 kbps
- 56 kbps
- 64 kbps
- 80 kbps
- 96 kbps
- 112 kbps
- 128 kbps
- 160 kbps
- 192 kbps
- 224 kbps
- 256 kbps
- 320 kbps
AVFoundation framework AVAudioPlayer supports the following:
- mp3
- m4a
- caf
- aif
- wav
