Active Noise Canceling Hearing Protection

Noise attenuation can actually help in hearing some forms of noise outside of the drone of the engines.

I can hear the radios better and my cell phone ringing when I wear ear plugs on the assistance towboat where I sit on the engine box inside of a small cabin.

Noise cancelling if designed for a specific freq range can actually help a lot when listening for noises outside that range and will help in earing things out of the ordinary.

Psneeld was quicker on a response to "Wouldn't If", thanks well said.
Al

BandB said:

Generally I'd agree with you, except knowing some very well insulated engine rooms on some quality boats that still have a problem. Hatteras is a fine builder but their boats with the CAT's are generally loud. A 60' Hatteras with twin 1135's hits 76 db at 1000 rpm and 10 knots. From there it rises until it reaches 84 db at 2250 rpm.

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Hatteras makes very little effort at noise control and when they do its more a nod than any real effort. Very few production builders give more than lip service to noise control. The previously mentioned Cabo is a fine example of missing the noise reduction opportunity. On the 45 Express the helm pedestal is mounted on a box that if you open it you see the hull vents that bring combustion air to the engine room. No insulation whatsoever, just a thin solid molded fiberglass box with a hatch in it and engine noise right behind it.

Anyone handy at all could spend very little and get some measurable reduction without much effort at all. Just gaskets and cable path treatments could make a noticeable dent. By installing real insulation the reduction could be substantial.

I put acoustic carpet underlayment in my Mainship 34 and could have a conversation in the salon underway without raising my voice. Was easy.

We used them extensively in aviation and they aided in hearing other noises by eliminating much of the 'droning' noise of the engines and air over the fuselage. With full-ear muffs which surround the entire ear lobe, there is an element of passive noise suppression like you'd get from typical ear muff style headsets without ANC. The electronic ANC component works best on the constant frequency noises.

When my kids were studying sound waves in high school, I brought a pair of ANC headphones home to demonstrate their effect. The sounds of ceiling fans, refrigerator compressor, air handlers etc are immediately silenced by a significant amount by the ANC. Normal conversation could be heard, but was slightly attenuated by the passive noise cancellation characteristic of the full-ear muff.

I would tink the best of both worlds would be to have adequate passive noise suppression in the form of something like ER Sound-down panels and stateroom carpeting plus stateroom ANC customized to the dominant frequencies and seating/sleeping locations.

I love my Bose NC headsets, great on commercial flights as they drown out the cry's of children and young adults. They do attenuate sounds passively as well as actively so they will remove sounds from all spectrum's of your hearing not just the engine running, that could be bad.

If I felt I needed then in the wheelhouse then I would figure a way to make the wheelhouse quieter.

Side note, I had a fellow passenger on a flight inbound to Orlando (ton-o-kidslets) that was sitting next to me offer me 400 dollars cash at the beginning of our 5 hour flight.... I said sure in 5 hours, sadly he said now or never. I still have them.

BandB said:

Generally I'd agree with you, except knowing some very well insulated engine rooms on some quality boats that still have a problem. Hatteras is a fine builder but their boats with the CAT's are generally loud. A 60' Hatteras with twin 1135's hits 76 db at 1000 rpm and 10 knots. From there it rises until it reaches 84 db at 2250 rpm.

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I don't think the trawler set is going to run a 60' Hatt at WOT.

At trawler speeds, say 9-10 knots, we would have to make no adjustment to voice levels. At 1800-2250, slightly raised voices but no yelling.

As someone in the CE business, I would strongly urge trawlerites to consider other brands than Bose, an incredible waste of money. You are paying huge (can you say 90-95%?)margins to cover marketing and the name. Take a look at brands like Shure, for instance.

caltexflanc said:

I would strongly urge trawlerites to consider other brands than Bose,.

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Unless your son in law works there and gave you a set for Christmas! ?

Al said:

Psneeld was quicker on a response to "Wouldn't If",

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He is quick, I'll give him that.

Just like electrical interference, you're much better off dealing with the source than trying to filter it out after the fact.

I frequently use a pair of V-MODA Faders VIP by Ear Armor, Inc that reportedly reduce noise by 12dB. V-Moda makes some most excellent headphones, and the engineering and thought that seems to go into their products is well worth the price. The faders are only 15 dollars currently, and I can attest that you can still hear everything you want perfectly clear as I use these for everything from concerts to cutting wood.

Looks like my post got marked as an advertisement, but really, I'm just giving an apparently too glowing recommendation for some junk I like!

The ANC hearing protection I had would cut off load noises, like gun shots, and lower the level of the tractor engine noise which was the primary reason I bought the head set. However, the unit would also amplify low level noise. I would listen to birds, tree rats and deer with and without the hearing protection in use. The headset would noticeably amply the very low level critter noise.

I think the ANC hearing protection I had would increase the ability to hear someone fall over board and call for help. Certainly one could easily test this by having someone at the helm listen for someone talking a good distance away and throwing something overboard. Hopefully, not the wife or noisy children.

Another thing to consider with loud noise is that it tires you out. If the noise at the helm is so noisy that it is bothersome, I would be concerned that the noise fatigue would reduce my reaction time and maybe prevent me from noticing a cry for help or splash of someone falling overboard.

Later,
Dan

This could morph into a single versus twin debate. At full cruise the Lehman 135 on Bay Pelican generates 63 DB of noise in the saloon directly above the engine room. I have ready earmuffs for any entry into the engine room underway.

Bay Pelican said:

This could morph into a single versus twin debate. At full cruise the Lehman 135 on Bay Pelican generates 63 DB of noise in the saloon directly above the engine room. I have ready earmuffs for any entry into the engine room underway.

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Or it could be builder vs. builder or engine manufacturer vs. engine manufacturer. Although not trawlers, I'll use these comparisons as an example of how major the difference can be with large engines of different brands on different boats. For instance, Westport with twin MTU's. A Westport Pacific Mariner 85' with twin 1500 hp MTU's 51 db at 750 rpm, 60 db at WOT or a Westport 130' with twin 2895 hp MTU's 51 db at 750 rpm, 60 db at WOT. Compare to Hatteras in the same size (Both 60' and 100') and hp ranges but with CAT and they are 67 db at 600 rpm and 85 db at WOT.

Nordhavn 50' with 250 hp Lugger. 65 db at 1000 rpm, 69 db at WOT.

Nordhavn 75' with twin 740 hp MTU. 62 db at 1000 rpm, 75 db at WOT.

Nordic Tug 34' with 260 hp Yanmar, 58 db at 750 rpm, 88 db at WOT.

KK 39' with 120 hp John Deere, 64 db at 1000 rpm, 76 db at WOT.

Sea Ray 510 Fly with twin 600 hp Cummins, 60 db at 600 rpm, 85 db at WOT.

Cigarette 38' with twin 550 hp Mercruiser, 81 db at 1000 rpm, 107 db at WOT. Can you say deafness?

I would look back at our discussions of what to look for in a boat and say that sound is perhaps one characteristic we've overlooked the most. We get out on the water for the peacefulness. Well, we own a boat that is 50 db to 60 db and another that is 71 db to 80 db. The latter might be labeled exhilarating but the former is sure a lot more peaceful. I would add sound as a characteristic to consider in a purchase.

I would add sound as a characteristic to consider in a purchase.

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I'm not sure where you get all those numbers, but emphatically agree with that last statement. I put my faith in a sea trial first and foremost as certain sound patterns bother certain people differently. Personally I couldn't own a cruising boat where ear protection is needed at the helm. I also think you have to be able to hear something, as changes in sound can be a key indicator of something going wrong.

caltexflanc said:

I'm not sure where you get all those numbers, but emphatically agree with that last statement. I put my faith in a sea trial first and foremost as certain sound patterns bother certain people differently. Personally I couldn't own a cruising boat where ear protection is needed at the helm. I also think you have to be able to hear something, as changes in sound can be a key indicator of something going wrong.

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Various boat tests. Powerandmotoryacht and boattest have the most. But sometimes there are other sites and sometimes the builder has tests. We chartered a lot for about a year and the differences we observed there were dramatic. The entire experience, just the feeling of calm, was so enhanced by quieter boats. If you're out for a high speed 40 mile trip it's one thing, but if you're taking a leisurely cruise it's quite different. It turned out to be important to us even though we did not have it even listed on our initial requirements.

SCOTTEDAVIS said:

I love my Bose NC headsets, great on commercial flights as they drown out the cry's of children and young adults. They do attenuate sounds passively as well as actively so they will remove sounds from all spectrum's of your hearing not just the engine running, that could be bad.............

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Unless there's a way to tune them to a specific frequency they are going to attenuate all frequencies and all sounds, bad and good.

FlyWright said:

...... I already have a 5-speaker Bose speaker system in my salon. How hard can it be to mount a couple of microphones and a processor to feed the reverse phase audio signal into the speakers to attenuate the ambient noise? I think it would be a much better option than wearing headsets..

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You would get nothing but a feedback howl. It only works if you can control the sound your ears hear and feed them an equal amplitude out of phase signal. Like with headphones.

rwidman said:

You would get nothing but a feedback howl. It only works if you can control the sound your ears hear and feed them an equal amplitude out of phase signal. Like with headphones.

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Have you ever been in an environment with active noise cancelling? It doesn't work that way at all. I have spent many hours in aircraft with ANC throughout the cabin and there is no feedback. That's just nonsense.

FlyWright said:

Have you ever been in an environment with active noise cancelling? It doesn't work that way at all. I have spent many hours in aircraft with ANC throughout the cabin and there is no feedback. That's just nonsense.

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Although I asked earlier, this was the same reasoning I was thinking of. Unlike your airplane (which has a fairly constant pitch, harmonic and drone) a boat sound varies with engine load, seas hitting, and other variables. I would think a boat equalizer would be way more complicated. No never been 'in' a sound attenuated environment. Wondering how it would work on a boat though.

Regarding your plane experience: is it 'On' all the time? Or only after reaching cruising altitude?

There is technology that will be coming to market soon that allows you to tune out specific noises and let in others. Even to the point of only canceling out someone's snoring, for instance. Pretty amazing.

cappy208 said:

Regarding your plane experience: is it 'On' all the time? Or only after reaching cruising altitude?

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It was selectable on/off, but it remained on during the entire flight. The concept is to reduce the droning sounds, leaving conversation and other signaling sounds audible. It works so great that once you operate with it on, you really miss it when it's off or inoperative.

I am going with Flywright!! "In theory there is no difference between theory and practice. In practice there is."!!:lol:

Al

FlyWright said:

Have you ever been in an environment with active noise cancelling? It doesn't work that way at all. I have spent many hours in aircraft with ANC throughout the cabin and there is no feedback. That's just nonsense.

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"Nonsense"? I thought we were supposed to be "nice" here? That's what I've been told anyway.

As a former electronic technician specializing in audio, I would really like a link on how this would work technically. I haven't seen anything like this available to the public (to reduce sound from nearby highways or airports, etc.).

Please explain how sound can be cancelled out in a large space.

Keysdisease said:

Effective insulation in the engine room or on the floor above I would think would be a more reasonable way to address pilothouse noise than having to wear ear protection. ...

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I agree. Can't you upgrade the sound insulation? One can hold normal conversations in my pilothouse directly above the engine, having rubber gaskets on the engine compartment lids as well as insulation in the compartment's ceiling and rubber engine mounts.

wow!!!!!

the shoe on the other foot....

markpierce said:

I agree. Can't you upgrade the sound insulation? One can hold normal conversations in my pilothouse directly above the engine, having rubber gaskets on the engine compartment lids as well as insulation in the compartment's ceiling and rubber engine mounts.

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Mine looks like yours with 4" or so of insulation and acoustical tile on the bottom (top of the engine compartment. Raising a hatch to check the running engine is obvious even from the flybridge.

rwidman said:

Please explain how sound can be cancelled out in a large space.

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??. That's how. Simple, huh?

If this was an easy thing to accomplish...... It'd be done already.

Big thanks to all who have contributed to the discussion. I am a regular on another forum that is primarily sailing oriented and it is no surprise that the responses (to this engine related question) have much greater depth on this forum.

O.K. so I found out that one of the noise canceling headsets that I use in aircraft is able to be used "on its own" (I previously believed that the headsets needed to be plugged into the aircraft intercom to activate).

These headsets are made for small piston aircraft (loud). They have large earcups with nice fitting earseals and provide a degree of PASSIVE noise attenuation much like any other simple muff type hearing protector. They also have active noise cancellation circuitry that is switchable on/off.

Today I gave the the headsets a try aboard Panope. Here is the deal:

-I was alone on the boat so I tuned the VHF to the continuous weather broadcast to see if hearing voices was a problem or not.

-I set cruising rpm at 2500 and listened to the VHF - everything normal.

-I then put the headphones on WITHOUT activating the ANC and found that Mid to High pitch sounds were attenuated from both the engine and the VHF. The VHF remained just as audible as before. The low frequency drone (the sound that I find bothersome after a couple hours) from the engine was basically unchanged.

-I then activated the ANC. The ANC on these headphones did not change the Mid and High frequencies at all. The ANC did not reduce the volume of the VHF whatsoever. The ANC on these headphones eliminated the low frequency drone almost entirely. Just what I was looking for. Wonderful!

-The attenuation of the low frequency drone caused the voice on the VHF to be much easier to hear. I was able to turn the volume DOWN on the VHF. Great!

I noticed that the headsets that I was originally considering ( ProTech NoiseBuster Noise-Canceling Over-The-Head Safety Earmuff Specifications. Call 203-210-7230 Noise-canceling ANR Safety Earmuff. Noise Reduction, Model: PA4000 Professional Industrial hearing protection. ) have ANC circuitry that ONLY attenuates the frequencies between 20 hertz and 800 (the audible range for humans is 20 - 20,000) I believe this corresponds well with the headsets that I tried today (I do not have manufacture data for these).

Panope's pilot house (see avatar) is directly over the engine. The pilot house sole is 3/4" Starboard. Starboard is quite dense and free of resonance. I have not yet added insulation to the floor (planning on Soundown). As a result of past experiences attempting to block low frequencies from 2 different aircraft (one wooden, one metal), I am not confident that the addition of Soundown insulation will produce a large attenuation of the LOW frequencies.

I downloaded a free Decibel Meter "APP" for my Android device. The readings in Panope's pilot house were 70 db at low cruise (1600 rpm) to 80 db at high cruse (3000 rpm) I cannot imagine that this "meter" is something to be accurate and reliable.

Note: I am a 6,000+ hour small aircraft pilot and all of this time has been spent with full size headsets on my head. My tolerance for wearing these devices may be much greater than others.

Steve

Steve, is that a Bose X you used in the air? I ordered Oregon Aero Soft Seal ear seals and soft tops to make earmuff style headsets wearable for 6-8 hrs each day. It was the best money I spent to improve the comfort of headsets.

Thanks for posting your results. Sounds like you might be on to something. (pun intended)

FlyWright said:

Steve, is that a Bose X you used in the air? I ordered Oregon Aero Soft Seal ear seals and soft tops to make earmuff style headsets wearable for 6-8 hrs each day. It was the best money I spent to improve the comfort of headsets.

Thanks for posting your results. Sounds like you might be on to something. (pun intended)

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Al, I am a David Clark fan. My normal headset is the H10-13X ENC Fixed Wing Headsets | David Clark Company | Worcester, MA I use the stock "gell" earpads.

The headsets that I tried in the boat today are an older set of Lightspeed 15xl Lightspeed Aviation - XL Series Headsets - Discontinued

I will give this a couple more days of thought before I make a purchase.

Steve