• The type of modulation, where the sampling rate is much higher and in which the stepsize after quantization is of smaller value Δ, such a modulation is termed as delta modulation.

• DM stands for Delta Modulation, a much simplified version of DPCM, also called as quick analog-to-digital converter.

• Here the difference between the predicted value and current value is coded with a single bit.

• Since a single bit will take only two values, the difference signal here only specifies whether a sample value here is greater than (positive difference) or less than (negative difference) than the previous sample value.

• DM is suited for signals whose sample values are quite similar.

• When applied to signals which change too rapidly, DM leads to a kind of distortion called Slope Overload Distortion.

• On the other hand, for signals which change too slowly, DM leads to another type of distortion called Granular Distortion.