A person's sleep disorders are resolved by applying low frequency vibration. Mechanical vibrators (1) present on a first side of a plate type base member (9) set the plate type base member (9) in vibration in such a way that its second surface transmits mechanical vibration. A plurality of first low frequency pulse trains (100; 101, 102, 103 . . . ) of mechanical vibration are conducted to a part of the person's body, at successive time periods (T; T1, T2, T3 . . . ). A frequency (f) of vibration in each individual pulse train (100) is maintained constant (f; fa, fb, fc . . . ) within the range of 20-50 Hz. The pressure pulses (400) of said pulse train (100) have a contact power (I) with said part of the body within the range of 40-70 dB. The constant frequencies (fa, fb, fc . . . ) of the successive pulse trains (100; 101, 102, 103 . . . ) are mutually different and change monotonously and mostly linearly. At least one second pulse train (100) is transmitted to said part of the body.