Frequency deviation measures one-sided swing while total variation doubles it

Evidence

In system theory, the deviation in frequency, L1f, is defined as the change in frequency between the unmodulated frequency, f, and the maximum frequency in one direction. Using this denition of L1f, it is important to note that the frequency changes between f - L1f and f + L1f· Thus the value for the total variation in frequency is 2L1f. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1055

Categorization

• DEFINE: Clarifies a system-theory term that otherwise carries ambiguity between one-sided deviation and full range.