Uniaxial stress dependence of acoustical phonon absorption in intermed
iately doped Ge:Sb has been studied using heat pulse technique. Abrupt
ly decreasing LA and FTA phonon scattering in stress interval of 3-7 .
10(8) dyn/cm(2) with further saturation up to 1.9 . 10(9) dyn/cm(2) w
as observed. Results obtained from phonon measurements correlate with
conductivity activation energy behavior on stress. Acoustical transpar
ency stress dependence is assumed to be connected with phonon assisted
electron transitions from impurity ground state D-0 to D- band.