Thanks fellow PPruners.
`Establish Communication' is to establish communication between crew members; ATC other aircraft are a later consideration with most airlines indicating a turn of track is preferarble due to traffic below bringing into consideration terrain clearance in some parts of the world.
As indicated and talking with others who have experienced decompression communication is/can be extremely difiicult due to noise particularly should the decompression be caused in a flight deck area and the comments about physical effects are noted.
The query is mainly from an airline angle where descending to a lower lever requires immediate passenger consideration however; whilst the prcedure may be taught/practised in simulator sessions airlines give very little thought, training or lectures on the reality of decompression parituclarly physological consiederations.
Defintiely a need for review of airline practices here and certainly regulators need to review their thinking.