The present invention relates to a system and method for operational acoustic optimization of a variable speed compressor (2) comprising a synchronous motor (6), a frequency inverter (3) and a control block (5), such optimization being carried out by modifying the switching frequency of the supply signal (9) of the motor (6) contained in the compressor (2), via a control block (5), only during the aligmnent phase of the motor (6), thus, not impairing the performance of the compressor (2), the thermal management of the inverter (3) and the acoustic performance of the system.