  We have put forwards a unified quantitative framework of vision and audition,
based on existing data and theories. According to this model, the retina is a
feedforward network self-adaptive to inputs in a specific period. After fully
grown, cells become specialized detectors based on statistics of stimulus
history. This model has provided explanations for perception mechanisms of
colour, shape, depth and motion. Moreover, based on this ground we have put
forwards a bold conjecture that single ear can detect sound direction. This is
complementary to existing theories and has provided better explanations for
sound localization.
