Speech recognition with image signal

A method of speech recognition, 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;
• for speech recognition, in one time duration of the predetermined length of speech to be recognized:
• comparing a combination of parameters of the speech signal and of the reflection signal with pre-recorded combined parameters of a speech signal obtained during a training phase and of a reflection signal obtained during said training phase of at least some of a plurality of pre-recorded time durations, wherein said combination of parameters includes information regarding said degree of light reflected by the mouth, and wherein said pre-recorded combined parameters include information regarding said degree of light reflected by the mouth determined during said training phase;
• wherein the training speech signal and the training reflection signal are coupled to letters associated therewith per time duration;
• 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,
• wherein block-width modulation is applied to the reflection signal.