The problem of the behavior of a point contact between normal metals in an alternating electric field with arbitrary frequency and amplitude is solved using the technique of quasiclassical energy-integrated Green's functions. The nonlinear components of the current due to the electron-phonon interaction are obtained. At the same time, both the frequency dispersion in the effective collision integral, which is important for ω∼ωD (ωD is the Debye frequency) and the frequency dependent effects of the renormalization of the electronic spectrum are included. The kinetic inductance of the contact [Kulik et al, Fiz. Nizk. Temp. 8, 669 (1982)] is proportional to the electron mass renormalized by the electron-phonon interaction m∗=m(1+Λ(e,V,ω)). For ω < ωD and when the bias voltage on the contact eV varies from 0 to ωD, the effective mass varies from m(1+λ~) to m where m is the band mass of the electron, which permits finding directly the electron-phonon interaction constant λ~ The constant component of the additional contact current arising due to irradiation, I(V), is proportional to the transport electron-phonon interaction function Gtr (eV).