afterwards the unapologetic cinema manager used a pen and paper to illustrate that this is "as the director intended" as i staggered around blind deaf in fear of airborne terminator attack. apparently to have it any quieter would spoil the dialogue, which would then spoil the film for everyone. i find this ironic with a film where not hearing the dialogue would make little difference. 'Terminator: salvation' is a story about the fight for survival after judgement day and arguably a post-apocalyptic world may not be a pleasant and comfortable experience, but people don't go to see 'Rocky' to get punched in the head.
i've had ringing in my ears for about 5 years now as a result of only a few hours prolonged exposure to high frequency noise (a pretty good description of Terminator 4). i will never in my waking life hear silence again. it's something i wouldn't wish for anyone, and certainly not something i would choose to pay for at the cinema. take care of your hearing.