Abstract: A call monitor apparatus for a speech processing equipment includes a digital speech processing equipment, a signal identifier, a switching unit, a decoder, a silent signal generator, a PCM converter, and a D/A converter. The digital speech processing equipment has a speech mode, a speech data mode, and a data mode. The signal identifier identifies an operation mode of the speech processing equipment and outputs an identification signal. The switching unit switches an output destination of the output signal from the speech processing equipment. The decoder converts an output signal from the switching unit into a .mu.law PCM signal when the identification signal from the signal identifier indicates the speech data mode. The silent signal generator outputs a silent .mu.law PCM signal when the identification signal from the signal identifier indicates the data mode.

Abstract: The method for executing coding subprocesses and decoding subprocesses calculates a first time interval from a current point to a variable output point of the coded output signals. Similarly, a second time interval from the current point to an output point of the decoded output signals is calculated. Second, a total processing time of a subsequent coding and decoding subprocesses is calculated. The subsequent subprocesses are both allowed to be subsequently executed. Finally, one subprocess to be subsequently executed is selected from the subsequent coding and decoding subprocesses by comparing the total processing time with a smaller one of the first and the second time intervals.