Interference/Feedback in Howard Leight electronic earmuffs

[rivviepop]

Yesterday while wearing the Howard Leight Impact Sports electronic muffs for an extended period of time (5 hours?), I got weird feedback 3 or 4 times that lasted for oh, maybe 5-10 seconds, and it seemed to come from the right side only. The sound was that "deet deet dit dit dit deet" sound that you sometimes hear in computer speakers when there's some interference, I've heard it before with other electronics. The batteries were/are fresh, volume was up to... maybe 1/4 or 1/3rd of the way (so pretty low).

Anyone else experience this with these muffs? If not, could mine be defective? Are these things sensitive to radio frequency like that, and maybe it was because I was walking by something that triggered the situation?

[cush]

That type of interference is typical from cellphones or blackberries.
Just part of their background operation, not actually making a call.
Happens to certain speaker phones at work. I've heard it on some car radios.
I heard it a bit on my Impact's last weekend but not much.
Somebody else was wearing a different brand and kept getting the local radio station, much more annoying.
-cush

[rivviepop]

OK cool thanks, that's sort of what I was thinking - I'll just deal, at $50 out the door I'm not expecting the worlds best electronics. They work for the intended purpose, it's just annoying when it happens...

[DedEye]

Sounds like the cell phone interference I hear on every piece of electronic audio equipment I've ever used.

[Jicko]

U will get feedback if you hold ur hand about 1" from the mic....

[rivviepop]

I don't know why I didn't think of this before... I put on the phones at about 1/2 level, picked up my BlackBerry and dialed voicemail. Yup, that's the sound all right that I was hearing at the range.

[trilogy]

rivvie, how do you like those earmuffs? I've heard good things and was thinking about getting a pair.

--Matt

[rivviepop]

rivvie, how do you like those earmuffs? I've heard good things and was thinking about getting a pair.

They seem to do all right - you have to fiddle with the adjustment knob a bit, I think they'd be better if they had a setting you could "see" (think like ticks or numbers on a volume dial), as I turned them off and on a lot and had to find the right setting by trial and error over and over. Good for a match where you want to hear talking & such a lot.

That's outside - inside, they're only NRR22 so you want to double up, not enough protection in my opinion. I went back to just using regular NRR30 Peltors at the indoor range, easier to manage.

[draconianruler]

I get that interference occassionally too. I'm still very happy with mine but havent tried any of the expensive brands yet so can't compare.

[DedEye]

I love mine; never had a problem with interference. The adjustment/volume knob lets you choose how loud you need it depending on the background noise and isn't a big deal to adjust.

[cush]

I like mine, no problems. We have 3 sets in my family and my brother has a couple.
I bought them at turners on sale. Normally Cheaper than dirt has the best price, but I checked they are $42 (were $38 I think) and are out of stock.
I chose them mostly as they seem to have less interference with getting a cheek weld on a rifle.
I haven't tried any other good muffs for comparison.
-cush

[trilogy]

Thanks for the info I will be picking up a pair very soon.

--Matt

[rivviepop]

One thing I did like - I was wearing your typical shooter lenses all day, and these muffs didn't compress in on my head that much and cause the eyeglass-arm-pain by the ear that you get with other muffs (like the Peltor blue ones). It did start to become uncomfortable a tad after the 5 hours, but was completely acceptable during the shooting day; one of the main reasons I hate muffs is because of that pain they start to cause, preferring instead to wear NRR30 earplugs.

[bwiese]

Consumer electronics is often poorly shielded from RFI/EMI.

It's just good enough to pass FCC compliance tests - usu a 'laboratory queen' device in a Hong Kong lab that supposedly complies with FCC testing. Later production cost-downs may allow much more emissions than what supposedly the device is certified for.

Many new flat TVs are so bad that if I were stranded on a desert island with a generator, the TV and a big roll of wire for an antenna, I'd have a fair chance of having a pretty good HF transmitter to get out a help message (with no TV modifications).

For your muffs, if you are handy w/electronics and this is a bothersome issue, putting bypass capacitors and RF chokes in the power line from batteries may help, along with - yes! - some tinfoil (grounded to '-' side) in the cups. (That could make things worse if it rattles w/audio, though.)

I suspect brands/models of muffs designed to be hooked to a 2-way radio (like my Peltor 7S) may have reduced RFI susceptibility because this concern would likely have been addressed in design.