The relaxation parameters of charge carriers in aluminum are measured by investigating the attenuation of electron sound and acoustic wave transfer under Doppler-shifted cyclotron resonance. It is shown that the electron–electron relaxation rate at spherical parts of the hole sheet of the Fermi surface is close to the results of the theory (A. Jaquier et al., Phys. Rev. B52, 13005 (1995)) that takes into account the electron–electron interaction with the exchange of virtual phonons. At the same time, the experimental anisotropy of the electron–electron scattering is considerably smaller than the calculated value. A noticeable anisotropy of the electron–impurity collisions frequency in aluminum is discovered.