Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Critical
Flight Crew Requested ATC Assistance / Clarification
Aircraft
During the initial climb; we experience several events of strong radio interference due to ACARS transmissions/crosstalk. This events caused both discomfort due to the very loud volume of the interfering transmissions and difficulty in understanding ATC communication.  Additional interference events occurred during the flight for a total of 15 events.  During the last six weeks many crews have been experiencing frequent events of radio interference due to ACARS transmissions/crosstalk. These interference events should be a safety concern. They caused; in more than one occasion; us to miss/misunderstand critical ATC communications and instructions during the departure phase of the flight. Something changed in the last few months; [however]. The intereference could be caused by changes in the ACARS communication software; protocols; procedures; equipment.  Usually after Weight Off Wheels both the FMS and the EICAS show an 'ACARS NO COMM' message; shortly after that a very loud burst of digital communication is heard in the pilot headsets. In the worst cases the interfering signal is repeated multiple times during the first few minutes after takeoff. There should be an investigation of these events. In the meantime pilots should be provided temporary procedures (like disabling the ACARS system) to be used during the departure phase of the flight.
CRJ700 First Officer reports strong interference from ACARS transmissions occurring after takeoff on most of his company's CRJ aircraft; making ATC communication difficult. The reporter believes that changes in the ACARS communication software; protocols; procedures or equipment since late December are the cause of the problem.