Analogue and digital sound Analogue sound Analogue sound is a wave recorded from the source in its original form. It does not change. And it is read and reproduced by an analogue player and amplify in a speaker. Some analogue devices are the tape and vinyl record. To process this type of audio, the sound wave produces a vibration in the air which gets to a microphone. This vibration travels through a wire as an electrical signal. It records on magnetic tape by using recording heads. These heads are also in charge of reproducing the sound. There is a loss of quality on each playing due to the friction between the tape and the heads that degrades the physical support. For the same reason, duplication in analogue sound (copy from one support to another) produces a loss of quality in each copy. Digital sound On the other hand, digital sound is kept, processed and reproduced in digital supports as numbers. There exist several supports to keep digital audio: MP3, CD-Audio, CD-Rom, DVD, hard drives, etc.. As in the previous case, the sound is kept by a microphone. But the electrical signal becomes numerical data by a sampler (analogue to digital converter). The sampler is placed between the micro and the recorder. This process happens several times per second and is called sampling.