Understand recording

2.1 Understand recording

Record sound on a PC is through a sound card, convert analog signal to digital. it controlled by the following parameters:
Bit Rate
	Bit rate (or bit depth) describes how many binary digits a digital audio file uses to describe the amplitude of the audio it is recreating. Each bit doubles the accuracy with which an amplitude level can be described (16 bit = 65,536 possible levels). Record on a PC , It can be 16 bit or 8 bit. obviously using 16 bit will create higher quality sound but need more storage

Sampling Rate (frequency)
	Sampling rate is the number of values (samples) measured per second in the conversion of audio from analog to digital. The rule governing sampling (the Nyquist theorem) states that in order to accurately reproduce a sample, The sampling rate must be equal to, or greater than, twice the highest frequency to be reproduced. Therefore, the standard CD digital rate of 44.1 KHz restricts the maximum sampled frequency to 22.05KHz. (For a point of comparison, Human hearing is usually said to be 20Hz to 20KHz). 3D MP3 Sound Recorder support following frequencies: 8, 11,16,22,24,32,44,48. the higher the frequency, the higher sound quality.
Channels
	It can be either stereo or mono Stereophonic sound, commonly called stereo, is the reproduction of sound, using two independent audio channels, through a pair of widely separated speaker systems, in such a way as to create a pleasant and natural impression of sound heard from various directions as in natural hearing Monaural (often shortened to mono) sound reproduction is single-channel. Typically there is only one microphone, one loudspeaker, or, in the case of headphones or multiple loudspeakers, they are fed from a common signal path, and in the case of multiple microphones, mixed into a signal path at some stage