by Steve Sevits
Some time ago I used a sound meter to measure the background cabin noise of my Tri-Pacer, in flight at cruise.  The results were astounding.  An ear drum shattering 110 db.  For a number of years I flew Colts and Tri-Pacers without adequate hearing protection, no wonder I have a measurable (but not disqualifing) hearing loss.  In recent years I've been wearing foam ear plugs beneath my headset.  Now that I've changed to an active noise canceling headset what a difference!
The latest round began in a most unlikely place, my dentist's chair.  It's okay, he's a pilot too.  It often amazes me how dentists can interpret the incoherent mumblings of a patient with a mouth full of dental appliances.  Do dental schools offer a course in clarvoyance or mumble interpretation?  The conversation went something like this:
dentist: "Noise canceling headsets are great, have you ever tried a pair?"
Steve: "Mummph,  gag."
Dentist:  "No?  You really should.  I got some and they are great."
Steve:  "Garumph, oommm, goo."
dentist:  "You really ought to try them, they make all the difference in the world.  I'll loan you
    a pair of mine."
That's where it started.  Anyone whose never tried a headset with active noise cancellation, is in for a surprise.  I never did to fly the headset borrowed from the dentist, but I did the next best thing by trying them out while driving the garden tractor.  A new world free from background noise was my reward.
Some years ago I had looked into an active noise canceling headset, but the $900 price tag quickly cooled my interest.  My dentist friend put me onto an affordable option.  Headsets, Inc. of Amarillo, Texas offers a low cost answer with a set of conversion modules which fit into your current headsets.  My headsets were originally purchased in kit form, so assembly was nothing new.
For a cost of $180 which is only 20% of the high priced active noise canceling headset my familiar headset took on the new magic of blotting out those annoying and fatiguing background noises so characteristic in a PA 22.
A single evening at the kitchen table with a few hand tools and a small soldering iron started with the removal of the conventional ear cup speakers, replacement of some wiring and installation of an electronic module in each ear.  The ear modules sense the background noise and create an out-of-phase signal which cancels out background noise.  The headset also gets an extra power cord which plugs in to a 9v. battery pack worn in a shirt pocket.  The headset functions conventionally and when the power pack switch is turned on, the noise canceling feature takes over, blotting out a very significant portion of the background noise.  The results are definitely high tech, but at a comparative budget price.  For those not interested in the do it yourself approach, factory installation is available.
Headsets, Inc. offers kits for David Clark(r), Peltor(r), FlightCom(r), Soft Com(r), Sigtronics(r), Pilot(r), RST(r), Hush-a-Com(r) and AV-Comm(r) headsets.  The package comes complete with all the hardware, explanations and wiring diagrams necessary to complete the conversion which takes a couple of hours.  The only real change in the headset, once you're done, is that the headset should always be worn the same way after the conversion.  The electronic ear modules are labeled right and left and proper placement is critical to functioning.  When the assembly was finished, the headset worked perfectly right away.
The Headsets people are great to do business with, even offering a 30 day money back guarantee in addition to their one year warranty.  Additional information can be had from their website at:  .   Call 1-800-876-3374 for an informative brochure.
The lower noise level makes for less fatigue and more pleasurable flying.  This kit is a real winner, I wish I had it years ago.
A noise canceling headset conversion might make an ideal gift for a pilot.