Pro-Ears hearing protection deal for TBN members

MChalkley · Apr 22, 2002

Dan - Mr. Moderator Muhammad was hoping it would make me less opinionated - it didn't work... /w3tcompact/icons/laugh.gif

Have you used the Pro Ears with a rotary cutter? Or anything else at RPM speeds? Not yet, at least not under actual cutting conditions. I hooked the Ammbusher up and wound it up to full speed, just to see what it sounded like, and the Pro-Ears were just as effective on the noise it produces, but I didn't cut anything with it because I've already seen (heard, actually) that they handle impact noises quite well.

Right now I cannot hear anyone in a car if they pull up behind me. Would you be able to hear someone drive up from behind you? I think I would on my gravel drive, but it would depend on the surface, I expect. I do think I can say with some certainty that you'd be a lot more likely to hear a car with the Pro Ears than without.

Did you get the Pro Ears Dimension 2 and have you tried to listen to the radio while running the tractor? Yes and yes. The way it works is by simply introducing the sound from the radio into the earcup unprocessed. The Dimension 2 headset comes with a mono cord, which means it takes an audio source from a radio and feeds it into one earcup only. If you wanted to hear it in both ears, you'd need to buy a "Y" adapter. Or, if you wanted to hear a stereo FM radio source, you'd need a cord that adapts the stereo output jack to two mono jacks, one for each ear. You control the volume of the radio in the ear cup(s) with the radio's volume control. (I haven't used the Pro-Ears with an FM radio, but I have used them a fair bit with FRS radios.)

As I mentioned in an earlier post, I'm working on a big project all this week, so they'll really be getting a workout. I'll let you know how they do.

patrickg · Apr 22, 2002

Paul T,

"a device that amplifies a relatively quiet sudden
noise selectively over a relatively lound constant noise by determining
the incremental dB level if it were in a different frequency range from the
constant noise."

Hey, I'll trade you LOUND for MUTE, call it even, and suspend all penalties for spelling errors, OK?

Paul, You have a pretty good grasp of the problem. You are right about needing a way to discriminate between desired and undesired components in the complex audio spectrum composed of what we think of as signal (voices and funny noises of interest) and what we call noise (distracting, damaging, and or uninteresting tractor sounds).

If the sounds were in a different portion of the freq spectrum there wouldn't be a problem. The dB levels and speed of onset wouldn't be needed to differentiate them and operate on them differently like boosting one and eliminating the other or whatever. The problem is that they are NOT necessarily different in frequency and are just a jumble of frequencies. "Aye, there's the rub", science fiction or "movie magic" temporarily suspended, separating a complex audio field into its constituent sources when their spectra are overlapped is way beyond what any noise muffs are attempting.

There are lots of ways to "work" on audio signals and I would be extremely grateful if someone were to step forward and lay out a practical means of separating audio signals in an overlapped band of freqs , by source, after they have been "mixed". Until then, my best guess is that it is essentially imposible or quite difficult B_U_T, oh by the way, compression techniques make no attempt to involve the time domain (frequency), just the amplitude domain (loudness).

I hold these truths to be self evident: 1. the audio compression method CAN boost soft sounds, 2.the audio compression method CAN reduce loud sounds, 3. the audio compression method can not do both at the same time.

So, in the presence of loud sounds, the soft sounds will be reduced by the same amount as the loud sounds, there will be no improvement in signal to noise ratio and what you couldn't hear before because the tractor was too loud will still go unheard. I have made no representation that someone might not "like" the way the world (with or without a running tractor in it) sounds to them while wearing compression type muffs. That is actually an entirely different matter. I haven't said that there might not be several truly appropriate applications for the compression muffs. I can think of some, and considered getting a pair for one of those applications but declined in order to apply the money to buying technology that will benefit me in the application of interest.

If I can still recall, I think I only explained why compression type muffs couldn't do certain things that needed to be done to achieve the desired effect in some applications. I'm sorry if you feel that I went too far in my remarks. I was NOT attacking the man, I was trying to debate the technology. I don't think there is a need for anyone to come to anyones defense or to get too excited about an engineering kind of discussion. I know that in general I have very high regard for Mr. M. and have read with great interest many of his posts and have profited from several. In this instance I think I made him a bit defensive, which I regret, especially because it has such a dampening effect on the interchange of ideas and information.

As to my practical experience with whatever kind of sound reduction technology. I have much more experience with compression technology, as a user, than active noise cancellation but have recently tried to catch up on the advances in ANR and think it has some distinct advantages that can not possibly be wrung out of compression technology (I really think an integrated system with both has greater merit than one or the other) but then I don't think that was really why you asked so I won't continue straight ahead on this. Instead, this. I haven't much practical personal experience in a lot of activities that I think I understand quite well. I don't have to try out the gallows or guillotine to have a level of understanding of their operation sufficient to counsel someone on their appropriateness for certain limited applications. If someone chooses to "believe" for example that a tourniquette is appropriate first aid for nose bleed, I might suggest other technology and discuss the pros and cons. If in the end they like their choice, if it "works" for them, then fine.

If you remain unconvinced regarding the way I explain how the technology works then we have failed to communicate and as I only continued this because I hoped to succeed in explaining the technology adequately then I have failed and think I should bow out, there being little or nothing to gain by continuing the exchange.

Whatever anyone decides regarding muffs, at least consider some protection, passive NRR, active ANR, or Compression but use something. Practice SAFE TRACTORING. In the short run, noise causes fatigue and detracts from the fun. In the long run noise exposure causes cumulative hearing loss that can easily go undetected until a lot of sensitivity has been irretrievably lost. Most people who have lost significant sensitivity did not realize it due to the gradual nature of the loss (until it has become quite bad). I like my seat time but I like what I have left of my hearing too.

Patrick

MChalkley · Apr 22, 2002

Patrick - I know that in general I have very high regard for Mr. M. and have read with great interest many of his posts and have profited from several. Thanks. /w3tcompact/icons/blush.gif

In this instance I think I made him a bit defensive, Maybe a bit, but it's more a case of confusing me (I'm easily confused). I'll take your word for what is and isn't possible from a technological standpoint, since you obviously know more about it than I do, but I used them all day today, and I still say they simultaneously amplify quiet sounds while quieting loud ones. I don't know why there's a discrepancy between what you know is impossible, and what I'm hearing in action, but there is one - and it's considerable. I'm paying a lot more attention to what I'm hearing since your comments, but I still hear the same thing I heard before

which I regret, especially because it has such a dampening effect on the interchange of ideas and information. No regret necessary, no harm done, and no dampening took place. I'm still confused, but I'm used to that.../w3tcompact/icons/wink.gif

PaulT · Apr 23, 2002

"Methinks thou dost protest too much"

I really don't want to stir the pot, but I do want to clear up some of the confusion that has been introduced by saying certain things are impossible. Like Mark, I too was willing to defer to your superior knowledge in all things audio, until you stated this...

compression techniques make no attempt to involve the time domain (frequency), just
the amplitude domain (loudness)

As a younger fella, I used to love to make recordings (on tape, none of this newfangled cd-burning back then). Naturally I used Dolby Noise Reduction. I recalled reading about that technology way back when. It seems they BOOST higer frequency noises while holding lower frequency noises constant during the compression phase. So I went to their web page <A target="_blank" HREF=http://www.dolby.com/cassette/bcsnr/common.html>How Dolby Works</A>, and I found this picture.

What the accompanying text on the web page says is that the soft sounds are boosted, or made louder, relative to the loud sounds. Clearly compression techniques have not only made attempts to involve the time domain (frequency), they have actually succeeded at it (quite well, and for quite a while).

One could continue to argue whether these muffs actually use these techniques or not, but certainly one cannot continue to argue that these techniques are not available to the makers of these things.

When a man portrays himself as an expert to a believing audience, that audience will usually be swayed by the opinions presented when they are presented as facts. If that person is only speculating on things he suspects, and is wrong, he will have done a great disservice to the audience. I have been guilty of this from time to time. Please take extra care when expressing opinions to point out that they are merely opinions, and not facts presented by an expert. This site works because of the quality of BOTH the facts AND the opinions as well as our collective abilities to tell the difference between the two.

patrickg · Apr 23, 2002

MChalkley, The good news is that you are using something that actually helps protect your hearing. That you actually protect your hearing is much more important than how you protect your hearing.

There are often significant differences between human perception and instrumented data collection. Sometimes it is a simple phenomena and sometimes quite complex but not an infrequent happening. These recent discussions are exceedingly bland compared to those between acoustic engineers and HiFi-purists-with-golden-ears. Just as with music, where with blind listening tests, near totally perfect reproduction is frequently passed over in favor of something that sounds BETTER (to a listener). Nothing wrong with that. Who is to say how much sugar you should put in your coffee to make it taste the best, but you?

If you are pleased with the subjective "feel" of your selection and since it IS PROTECTING your valuable hearing, that's great. Another plus for you is that you have something better than "plain muffs" on your head working for you while I still have just the plain muffs because I am (probably OVER) complicating my decision process. I guess there is such a thing as knowing too much about something and getting bogged down. If I didn't have any alternative such as wearing regular muffs I guess I wouldn't have the luxury of anguishing over my selection.

Now if I could just get Kubota to email me back as to why in my owners manual they advocate liguid ballast and then say don't do it if you have a cab, I could get on with deciding how to design a counterweight and do something useful to my tractor's utility and functionality and my safety.

G'day

Patrick

patrickg · Apr 23, 2002

PaulT, I think this is continuing way beyond the appropriate scope of this forum. I am familiar with Dolby and how it works. Doesn't apply to what I meant. Maybe we aren't communicating as well as we could/should. Anyway if you would like to continue in private so as not to waste more public bandwidth I would be pleased to debate and discuss the technical issues till the cows come home, leave, and come home again (you might have noticed that tendency already) If at least one of us learns something from the exchange it will have been worth it. I don't have a problem with being wrong with good basis and never hold a grudge or get irritated with someone just for knowing something better than I do.

A problem with some technical discussions here is that if you make a statement and use terminology that just happens to not be in someones experience then they feel talked down to. If you break it down for someone who is an expert he feels he is being treated as a child or something similar. It is tough in such a group as we have here to hit a happy medium and still communicate with crisp precision, sometimes complicated nuances. I know I don't always do a great job.

I understand your other comments. I'm sure if you want to continue privately we, as two reasonable guys, will learn from each other and discover what the actual differences in our understandings are and probably reduce those differences. At any rate I think it inappropriate to continue this in the "Main Meeting Hall".

Oh by the way, did I mention that I am emoticon challenged and that you have to sort of try to mentally insert the appropriate emoticons into my text?

Patrick

dmccarty · Apr 23, 2002

MChalkley,

Thanks for the info.

Can't wait for my TBN hat and what you experience this week with the
Pro-Ears. /w3tcompact/icons/smile.gif

The road I maintain has a new house that is finally occupied and when
I start mowing in a few weeks I would really like to at least have a
chance of hearing a car approach. I try to watch but the cars can come
up real fast. So the Pro Ears at least have a chance of making this
happen. The road is gravel so that helps. /w3tcompact/icons/smile.gif

And if I could listen to a radio/tape/CD while on the tractor that would
be extra gravy on top of protecting my hearing. /w3tcompact/icons/smile.gif

Thanks,
Dan

MikeH · Apr 23, 2002

Mark,

Thankyou for this very informative review. It's this kind of information that makes TBN so great !

Just one question, will these be refered to as "MChalkley Ear Cups"? /w3tcompact/icons/laugh.gif

Mike

blurrybill · Apr 23, 2002

Patrick,

I don't pretend to know a thing about audio engineering. I do find it interesting that you so quickly acquired a concern about wasting "public bandwidth," given the extraordinary length of your posts on this thread. It seems to me that those of us who can weather the pontification on the subject can endure more dialogue between yourself and others who desire to opine. If anything, the previous posts may have continued "way beyond the scope of this forum." That said, I support your right to attempt to enlighten all TBN members in areas of your particular expertise. At the same time, I believe that paternalistic editorializing should be avoided. Trust us, Patrick, we can handle a good discussion here in the "Main Meeting Hall." Awaiting your succinct reply,

Bill

patrickg · Apr 23, 2002

blurrybill, OK, OK, so you don't think this has gone on too long. I was late in getting there but I did. When folks start drifting off the technical subject into ad hominems it has gone on too long or to wrong. If I am at fault then I can do nothing better than stop fanning it as I can't go back in time and do it different.

I have no ax to grind with anyone on this topic. I respect the fact that everyone has an oppinion and the right to share it. I don't mind continuing IF we debate and discuss the technical issues and not stray toward personal attack.

I wasn't declaring victory and leaving the field. I just thought it was overdue to stop grinding on this topic. Without sharing a certain background, communications of a technical nature can be hard. I am not the best explainer in the world, in case you didn't notice. As I said previously if I go peer to peer and someone doesn't have the credentials he may think I am "snowing" him. If I break it down it gets real lengthy and the person on the receiving end might think he is being treated like a child. Neiher of these mismatches is conducive to good communications.

I would bet a hundred dollars if everyone got together in one place I could do a show and tell that would easily demonstrate the practical side of the theoretical stuff I have attempted to explain. I could probably do it with just a blackboard and a few minutes attention.

If you are serious about wanting to understand enough of the technical side of why I said what I said and not just looking for a tis taint tis taint then I will try my best to explain whatever I can of what you ask. If you have some specific questions I will be happy to try to answer them. If there is a general part of my explanation that is unclear to you, point it out and I will try to cover it better. I know that sometimes I don't say everything I am thinking and what seems like a crushingly logical progression of concepts leading unswervingly to MY conclusion (to me) is somewhat like having a swarm of bees buzzing in your head (to the other guy).

I highly recommend http://www.avweb.com/sponsors/litspeed/anr101.html It is pretty good stuff, not oppinion, just easily digested tech info. I know we are not discussing flying an airplane but operating a tractor. I know we will discuss "compression", tractor noise, signal to noise ratio and other stuff. The ANR tutorial will give you a leg up with some of what will have to be discussed if we continue.

Standing by...

Patrick