Sound is recorded by the decibel (volume) samples an object makes over time.

Types of sounds:

Audio calculations for an uncompressed audio file:

sample rate x seconds length x (bit resolution/8) x channels of sound

10 seconds of 22 kHz audio in mono sound is:

22,000 x 10 x 8/8 x 1 = 220,000 bytes

Audio compression - generally lossy (you loose data)

Codec are used to encode/decode the files. Make sure you use a standard codec available on the user's PC.

Streaming Media

MP3 (Info gotten from here)

As a form of compression, MP3 is based on a psycho-acoustic model which recognizes that the human ear cannot hear all the audio frequencies on a recording. The human hearing range is between 20Hz to 20Khz and it is most sensitive between 2 to 4 KHz. When sound is compressed into an MP3 file, an attempt is made to get rid of the frequencies that can't be heard. As such, this is known as 'destructive' compression. After a file is compressed, the data that is eliminated in the creation of the MP3 cannot be replaced.

When encoding a file into MP3, a variety of compression levels can be set. For instance, an MP3 created with 128 Kbit compression will be of a greater quality and larger file size than that of a 56 Kbit compression. The more the compression level decreases, the lesser the sound quality and file size.

Details on how MP3s work

Text to Speech - Download

Speech Demos