We discussed the brain mechanisms of audiovisual integration and semantic comprehension as a direct process of comprehension (early integration) and process with second tuning (late integration) necessary in conflict situations. Existing of such audiovisual semantic conflict and four strategies to solve it were obtained in psychophysical experiment. Mathematic models were formulated according to that data. All models were described by linear equations, which were noted for the different weights of contributions of audio and visual modalities.