A method of speech recognition and person identification based thereon, comprising: recording speech from a speech signal using a microphone; illuminating a speaking mouth; recording a degree of light reflected by the mouth from a reflection signal using a sensor; and recording combined parameters of the speech signal and of the reflection signal, and coupling them to letters associated therewith, per predetermined time duration; comparing a combination occurring in speech of parameters of the speech signal and of the reflection signal to the recorded combined parameters of the speech signal and of the reflection signal which are coupled to letters; and deciding on the basis of the comparison to which letter the combination occurring in the speech of parameters of the speech signal and of the reflection signal corresponds, using block-width modulation of the reflection signal.