Method of approximating the amplitude of an analog signal sample and recording it in terms of bits. Quantisation takes the maximum amplitude or height of a given signal and divides it into a number of small pieces that are stacked on top of each other to reach the highest amplitude. The actual amplitude value falls somewhere within one of those stacked blocks. That block is then given as the height of the signal at that sample. f the blocks used to measure a sample are large, the amplitude values are not very accurate when reproduced (the resolution is low). If the blocks are very small, their values are closer to the true values of the amplitude at given samples resulting in a more precise reproduction. Think of a ruler that only measures in inches. If you draw a line that is three and a half inches in length, when it is quantised it will be given as three inches. If the quantisation blocks are smaller, say one eighth of an inch, then the approximated value is very close to the real value. n digital reproduction, quantisation is determined by the number of bits used to record the quantisation blocks. With more bits, there can be more blocks resulting in signals more closely resembling the actual signal. CD digital audio uses 16 bits to represent the height or amplitude of each sample. These 16 bits allow for the use of 65,536 blocks to form the quantisation (two to the sixteenth power – there are two possible values, one and zero, that can be combined across sixteen spaces to form data). Most professional recordings use quantisation values of 20 to 24 bits (resulting in 1,048,576 blocks and 16,777,216 blocks respectively – obviously much more precise than the 16 bits used for CD audio). he sampling rate combined with the quantisation affect the potential maximum quality of an analog signal converted to and then later reproduced from digital data. Higher fidelity audio systems would use higher sampling rates combined with higher quantisation to create a more accurate representation of an analog wave signal and thus be able to produce a better quality output closer to the original signal. The difficulty with using higher sampling rates and quantisation bit word lengths is that the resulting file size becomes increasingly large making storage of very high-fidelity digital audio a problem. It was for this reason that the format used for CD audio was chosen, it is a good compromise between ultimate sound quality and file size that affects storage issues and reduces the amount of audio that can be held. ome discussion is circulating regarding a new, high-definition audio format using DVD technology to hold data encoded at a 96 kHz sampling rate with a quantisation of 20 to 24 bits resulting a vastly superior audio reproduction format compared to standard CD.