Noise
Engine's recollection about noise and what action the RN took is accurate. In August 1998, having completed flight trials of the first fully integrated ANR in Sea King (that is, the helmet becomes an Intercom LRU as well as an AEA, as it is powered and sits within the TEMPEST boundary), DOR(Sea) asked me to prepare an Admiralty Board Submission to develop and introduce hearing protection across the FAA, including ground/deck crew. (Used to be a DGA(N) job, but they got rid of the posts in 1988 so I was paid to do something I'd done as a lad). I submitted it on 1 September 1998. Such things need a champion, and when the OR officer moved on matters seem to have slowed considerably.
Engines mentions other solutions. In 1995 the FAA specifically rejected in-ear devices, so ANR earshells were the only viable solution. The Sea King system was of no use in a Lynx for example, but purely by coincidence worked in a Sea Harrier. Different noise sources, but very similar frequencies. Janes DW published an extensive article at the time, and the Portsmouth MP (Hancock) raised it in the House, due to the threat of litigation. (Search ANR + Hansard). What made HQ twitch was the way the requirement was expressed, as 'allowable flying hours'. 600 were needed per year; without ANR only 59 were permitted, which of course was conveniently kept under wraps until Janes published. If you ever feel like submitting a claim, it's all on record......and backdateable to 1998.