Abstract: A method and apparatus are provided for determining the quality of a speech transmission, including temporal clipping, delay and jitter, using a carefully constructed test signal (300) and digital signal processing techniques. The test signal that is to be transmitted through a speech transmission system (100) is created (700). Then the test signal is transmitted through the speech transmission system such that the speech transmission system creates an output signal that corresponds to the input signal, as modified by the speech transmission system (702). The test signal includes multiple segments (500) of speech signals interleaved with periods of silence. The periods of silence vary in duration according to a predefined pattern. Each segment of speech signals includes multiple predefined speech samples or symbols (400, 402, 404, 406, 408, 410, 412, 414) interleaved with a plurality of silence gaps. The speech samples have a common period of duration, but the silence gaps do not.