To improve the performance of a digital signal processor without providing any additional device which is technically complicated and expensive by connecting a data memory, an inspection memory, and a calculating means to a signal processor calculation center part through a connection bus, and connecting the data memory and inspection memory to the calculating means.

An individual address bus ABUS and an individual data bus DBUS are provided for the digital signal processor. When this signal processor unit is in operation, a digitized sound signal is led to the calculation center part REK, which calculates an inspection feature vector from the sound signal and stores it in the inspection memory PSP through the data bus DBUS and a supply line 100. A data memory DSPE of the digital signal processor is stored with a reference feature vector representing speech features to be recognized, and those reference feature vectors are all compared with the inspection feature vector.