  We continue the development of a so called contextual statistical model (here
context has the meaning of a complex of physical conditions). It is shown that,
besides contexts producing the conventional trigonometric $\cos$-interference,
there exist contexts producing the hyperbolic $\cos$-interference. Starting
with the corresponding interference formula of total probability we represent
such contexts by hyperbolic probabilistic amplitudes or in the abstract
formalism by normalized vectors of a hyperbolic analogue of the Hilbert space.
There is obtained a hyperbolic Born's rule. Incompatible observables are
represented by noncommutative operators.
