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1/12/05
The Vendee Global, by Jeffrey Beckwith

The Vendee global is a sailing race around the world, for singlehanders, without any stopover. The race starts and ends in France and is sailed on 60 foot sailboats called Open 60's. The article below is one skippers observations of the noise experience inside the hull of one these high performance sailing vessels. The following paragraph from that article reminded me of easily I can be distracted and how important it is to separate the signal from the noise. "On board the average noise is around 90dB, with the most common being low frequencies around 1000 Hz, which is the most tiring for the ears. This is for example, the noise of the keel, the water against the hull or the noise of the engine. They cover up the higher pitched sounds, which are more informative. Harmful and tiring, these continual low-pitched sounds require permanent attention to filter them out to hear the useful information. It affects the level of vigilance, reduces efficiency and clear thought leading finally to strategic mistakes or unforeseen dangers."

Lying in his bunk, he tries in vain to sleep. He really needs to, but the water that is slapping on the other side of the thin layer of carbon on the hull just a few centimetres from his ear is there to remind him that he is going quickly, very quickly. The boat is on the crest of a wave. It feels like they're stopped. He can clearly hear the noises from outside, the whistling of the shrouds, the low murmur of the mast, the rattling of the halyards, the vibrating of the sail, and the groaning of the breakers. The boat heels over under the pressure of the wind. Pushed on to the slope of the wave, the hull swings downwards. And they're off again. Things accelerate like on ski slope. At this speed, everything vibrates inside the cabin. The boat is now level. She takes off again. It feels like falling into a bottomless pit. The vibrations get louder, with the keel adding a strident low-pitched noise.

We're doing more than 20 knots. The noise is everywhere and covers everything. The water spread out by the bow explodes and trickles down the hull. Euphoria and apprehension. The breaking is brutal. The stem disappears slams into the previous wave and disappears under the water, which floods the deck. It feels like the boat will never come out of the water again. You hear the strain on the rigging and the sails. Will they hold? The wind is so strong and the waves so huge, and land so far away. Then the next crest arrives, the boat comes out of the wave, rides up and swings over accelerating once again to start the journey again. Those monstrous waves that the boat rides over in a never-ending surf take everyone towards another self. This is the real adventure. This crazy head-spinning feeling of extreme speed, where pleasure and fear come together, as you approach the limits.

Things can get even more extreme in a force 10, bringing you out in a cold sweat, with a taste of saltiness in the background. Then, there is the wild and monstrous wave, which turns the boat over, breaking the mast, or the growler, the ice just floating on the surface, which can cut the hull in two. You really need some peace and quiet to relax and forget the endless constraints of this machine being pushed to the edge. That's impossible. The seas are too huge, the low too big, and the winds too strong. In this enclosed cabin space, the movements and noises are so present and sometimes so violent that you cannot get away from them. Violin, guitar or double bass, a boat is a magnificent stringed instrument, with the shrouds and sheets vibrating to the rhythm of the air, the halyards set the time and the keel plays the bass. The carbon hull is a magnificent resonance box, in which you have to live for more than 3 months.

He dreams of some quiet pieces to relax. It won't be for today. The score is quite heady but more thumping hard rock with solos above 120 dB. You heard right. Above 120 dB, like a clap of thunder on top of a chain saw going full out. Only a plane taking off is louder reaching 140 dB. The jackhammer only manages 110dB. On board the average noise is around 90dB, with the most common being low frequencies around 1000 Hz, which is the most tiring for the ears. This is for example, the noise of the keel, the water against the hull or the noise of the engine. They cover up the higher pitched sounds, which are more informative. Harmful and tiring, these continual low-pitched sounds require permanent attention to filter them out to hear the useful information. It affects the level of vigilance, reduces efficiency and clear thought leading finally to strategic mistakes or unforeseen dangers.

Close your eyes and think of something else. But the ears continue to hear. Nature didn't do a good job. Why didn't they provide muffs for the ears like eyelids for the eyes. There are always the plugs and earpieces, which are compulsory for work above 85dB. However, these devices shut out all the noise. It's impossible for the competitor, who wants to listen to his boat living and suffering. Always listening for suspect sounds, he interprets each little noise, analyses it, finds the cause and is reassured, before he gets used to it as an everyday companion. It was a permanent rattling that enabled Rolland Jourdain to discover the problem at the top of his keel, before it was too late. It is much wiser to filter out the unnecessary sounds to hear only the useful ones. That is the principle behind the anti-noise headphones, which filters out the bass sounds to keep the high pitched sounds. Inside each earpiece, there is a microphone, some electronics and a loud speaker. When sound waves pass through the ear piece, the system picks them up to instantly produce inverse waves in particular in the lower frequencies. The result is simple, initial wave + inverse wave sent at the same time = neutralisation. The wave is flattened, so there is no longer any noise.

It is remarkably efficient, with a stereo effect that removes the feeling of being shut in that you usually get from headphones. The sounds with higher frequencies, -radio, human voice, electronic devices, remain perfectly audible. Several research programs carried out by Doctor Bernard Destrubé over the past four years have shown the effectiveness of the system. The world of ocean racing was a fascinating laboratory, showing that beyond the competitive element, sailors can be used to perfect the technical solutions for others. Thanks to this work, headphones like these are now used by fishermen, who encounter a similar noisy environment. The Vendée Globe competitors quickly understood the advantages of the system to offer themselves some sleep of quality, thus making them more vigilant and offering them better recuperation. A lot took these headphones on board and they use them everyday to listen to music, to relax or to sleep. Some eyelids for the ears, if you like!

Jean-Yves Chauve