Speech speed is measured and displayed with our specific algorithm TEMAX (Temporal Evaluation and Measurement Algorithm by KS). The TEMAX-gram, a sonagraphic output of speech envelope, the DFT using a 1-second window is convenient to set off isosyllabic characteristics. For Japanese traces 2 dark bars, called rhythmic formants: RF1 and RF2: the first one, around 8 Hz, and the second one, at halfway. RF1 corresponds to speech rate, RF2 represents the bimoraic rhythmic foot. As far as English, its isochronic characteristics are observable with a 2-seconds window as RF1. Furthermore, using a 1-second window the periodicity of syllables between stress is displayed as RF2.