[en] The inhibition of the total HI n↔1 transition rate by delayed resonant reabsorption of HI (n+1)→1 photons by HI n→1 line which is possible due to cosmological redshift is considered semianalytically. The method taking into account this effect in the frame of simple three-level approximation model of recombination is suggested. It is confirmed that the resonant feedbacks affect ionization fraction at the level about 0.2% for the epoch of last scattering. Similar consideration of HeI 2¹P↔1¹S↔HeI 2³P↔1¹S feedback for helium is provided. It is confirmed that allowance of this feedback leads to an increase of predicted free electron fraction by 0.12% at z≅2300. It is shown that taking into account absorption and thermalization of HeI 2¹P↔1¹S resonant superequilibrium photons (during their redshifting to the HeI 2³P↔1¹S frequency) by a small amount of neutral hydrogen (10^-7-10^-4 of total number of hydrogen atoms and ions) existing in the helium recombination epoch is important for correct consideration of this helium feedback.