Reporter states that the air conditioning system causes noise so loud in an ETOPS B757-200 that the crew can easily miss an ATC communications. A noise canceling headset and third crewmember could help mitigate noise related missed calls.

Narrative

Missed radio call/ frequency change from Boston Center. Top of descent. Excessive noise in cockpit from air conditioning packs. All pilots (including Relief Pilot) on headset. Pilot flying was briefing the approach to pilot monitoring and Relief Pilot. Due to excessive noise; the briefing had to be given at a voice level which could not compete with the noisy cockpit. The pilot monitoring and the pilot flying missed the radio call as a result of the excessive noise. Fortunately; the Relief Pilot heard the radio call and saved the dayThe cause was an excessively noisy cockpit. This is a recurring problem with several of the ETOPS 757's. Previous reports have been submitted and discussed with the Senior Check Airman. I have suggested equipping all of the affected aircraft with noise cancelling headsets and always dispatching these flights with a Relief Pilot to help mitigate the effects of noise and resulting fatigue. I was informed that this was not possible due to 'manning issues.' It appears that economics takes precedence over safety regarding this potentially serious issue.The fleet manager informed the pilot group over 1 year ago that this issue would be addressed and that a fix was imminent. That has not yet occurred and it is understandable that logistics may impede this process. Nonetheless; amelioration of the effects of the noise and fatigue should be addressed in the interim. Active noise reduction (ANR) headsets and the scheduling of a Relief Pilot on all ETOPS flights would be a proactive approach to safety while the aircraft are being modified.