Thursday, February 16, 2012

One Last Note About Sound

Here's a fascinating follow-up to earlier this week (source wishes to remain anonymous):
Having spent 7 years and 7 months at sea on both aircraft carriers and "amphibs" - essentially an aircraft carrier for helicopters, I thought I would share a description of all the various noises one hears when at sea after reading today's update. So, here goes.

1) Flourescent light hum - 24-7. Even at night, when the white lights are turned off, the "red lights" are turned on. Red lights are nothing more than the white flourescent lights with a dark red tube placed over them.
2) 6 am - 10 pm - Announcements over the ship's speaker system at minimum of every 15 minutes. Special announcements don't count and happen whenever. One can tell time by the regularly scheduled 15 minute announcements in addition to the "Ship's Bell" which is rung every half hour during that same time frame.
3) Air pockets popping against the side of the ship. When a ship moves in the water, waves move in and out. Occasionally, air pockets form between the ship and the waves. What happens when a wave collapses that air pocket against the side of the ship - a very loud bang. Almost as loud as a gun shot being fired a few feet away. Completely random when those happen.
4) Aircraft Carrier specific - Catapults firing. There is a giant metal rod which has to stop somehow when it is used to sling an aircraft into the air. Guess what it hits? Yep - a giant metal stop. Result - very loud bangs which happen to be right next to some folks sleeping areas. (Yes, we learn to sleep through it).
5) 400 Hz hum. In certain parts of the ship are 400 Hz generators which are necessary to power test equipment, so things can get fixed. Those generators and their respective breaker panels actually emit a constant hum. The end result of this sometimes is hearing loss of 400 Hz tones. It does self-correct by being away from the hum for about a week.
6) Ship's alarms. Every morning around 8am, they test the audio component of the ship's alarms. These are very loud. If you happen to be working nights, you had better learn to be able to sleep through them, but also be capable of waking up when they are real. Nice contradiction, eh? Not to mention the GQ alarms where it depends on if you are ship's company or attached to a squadron to determine how you have to respond. Let's just say squadron life is a bit easier other than having to work on the flight deck.
7) This isn't sound, but when the ships are moving, their is a constant subtle vibration. The faster the ship moves, the more pronounced it becomes.
8) None of this includes - people talking, hatches opening and closing, folks walking up and down the metal ladders with their steel toes boots (which everyone has to wear), televisions when they are allowed to be on (after 6 am/before 10 pm), the sound of showers running when they are near berthings, flushing toilets, random noises from folks getting stuff in and out of their racks.

This could go on for quite awhile and it is truly surprising how much noise is generated and how one can struggle sleeping when it is not present immediately after leaving the ship.

The biggest thing, though, as the other person mentioned, when the power goes out, the silence is so sudden and so out of place, you immediately notice something isn't right. With no power, the ship stops moving. No more popping air pockets. No more vibration. The combination of missing sounds and vibrations is what wakes folks up so quickly.

What this has created in me, which can be positive and negative, is an intense focus on whatever I happen to be doing at the time. If I am writing a post or reading, someone could be sitting right next to me and trying to talk to me, but I won't notice a) if the reading has grabbed my attention or b) whatever I am writing has my mind centered upon it. It's like I can eliminate outside noise or visual cues when focused on whatever task and can sleep with music going, a tv blaring, someone vacuuming the house, mowing the lawn outside the bedroom window, whatever. Prior to the time on those ships, any kind of visual or audio stimuli would prevent me from sleeping. When studying, it had to be in a quiet environment. Now... completely different. The negative aspect of that kind of focus is pretty obvious. So... working on trying to become more normal again, but kind of glad to know I can tune out the noise or vision things when it is time to tune them out. Just have to learn to be more aware of friends and loved ones around me when they are trying to engage in a conversation if I happen to be doing something else at the time.

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