I’m Peyton Haynie from Bay City, Tx. This is for week three of Introduction to Music Production at coursera.org. I will be talking about analog to digital conversion.
Analog to digital conversion is an electronic process in which a continuously variable (analog) signal is changed, without altering its essential content, into a multi-level (digital) signal.
Step one – Sampling
Generally done with a sample-and-hold circuit, sampling is a process which involves taking “snapshots” of audio signals at fast intervals. The quality of the audio is largely determined by the sampling (or bit) rate.
Step two – Quantization
Quantization is the process which converts the sampled signals, which are continuous in value, into a signal that is discrete in value.
Step three – Coding
Coding is the process in which quantized signals are converted into a digital representation. Coding is performed by giving each quantization level a label. For example, when using four bits, the lowest level would be 0000, the next 0001, and so on.
Receiving and Decoding
After the signal is coded it is sent to a digital receiver. The signal is then decoded and reverted back into analog to be heard through speakers.
To summarize: to convert an analog signal into a digital signal, the signal is first sampled. Then each sample is quantized, and the values mapped into bits. The information is then sent as a digital signal to a receiver, where it is decoded and the analog signal is restored.