9 Voice activity detection

26.4413GPPCodec for Enhanced Voice Services (EVS)General overviewRelease 17TS

The Enhanced Voice Services codec VAD function is described in [2] & [11].

The input to the VAD is the input speech itself together with a set of parameters computed by the EVS encoder. The VAD uses this information to decide whether each 20 ms encoder frame contains active signal or not.

The VAD algorithm is described in [2], and the corresponding C-code is defined in [3] & [4]. The verification of compliance to [5] is achieved by use of digital test sequences applied to the same interface as the test sequences for the EVS codec.