Choosing The Right Pilot Headset

choosing the right pilot headset

The Sound Of Silence

Mark Smith looks at why you need a headset that will keep your hearing fit for flight
Courtesy Australian Pilot : Aug-Sept 2016

Your flying lessons are progressing well. Up in the sky your instructor is doing less and less of the flying and you begin to realise you really are going to be a pilot.

Yet after paying for books, theory classes and the lessons, you can't decide if your own headset is much of a priority.

The tired old ear protection, held together with tape, which is shared by all the students at your flying school hangs loosely off your head, contrasting sharply with the smooth lines of the set of Bose ANRs the instructor is wearing.

But they work and you can hear most of what's being said. Then, while doing stalls they fall off, again! The time has come. So what do you need to look for in a headset?

Active noise reduction, passive noise reduction, dynamic or electret microphones, flex or wire boom? What does it all mean and what do you really need?

Headsets have only become essential aids in the cockpit since the mid 1980s. Students learning to fly before then usually had a hand held microphone, a speaker in the roof and an instructor with a loud voice.

Many students returned from their final four hour solo nav quite deaf from the continual noise of the engine, much like pioneer aviators did decades earlier.

The system worked but it wasn't conducive to healthy hearing. Dr Warwick Williams is senior research engineer with the National Audio Laboratory in Sydney. He's adamant pilots need the best hearing protection they can get in the noisy environment of a light aircraft.

"It's very important to have protection for your ears in continuous high noise situations. Light aircraft, especially older ones, don't have very good insulation against noise so it's vital to block out as much background noise as possible, not only to preserve hearing, but so you can hear communications."

"Being exposed to the noise of an engine for a long period of time does cause deterioration in hearing. It's not a short term issue but one that creeps up over the years." Warwick believes you should buy the best headset available.

"Flying with a cheap headset is certainly better than none at all, but over time there is still the potential for hearing damage. Your partner will complain you have the TV turned up too loud, or you'll have trouble hearing speech when there is background noise."

A good headset is important to those of us who are getting a bit older as well. Age-related hearing loss, or presbycusis, is the slow loss of hearing that occurs as people get older. A good headset will allow you to accurately hear ATC transmissions against the background of the engine noise as you get on in years.

So, let's start our lessons in headset terminology. ANR, or active noise reduction, is a system where a small microphone in the ear cup picks up the constant low frequency drone of the engine and propeller and processes it through an electronic filter that mirrors these sounds 180 degrees out of phase before sending this tone to a small speaker also in the ear cup.

The result is a cancellation the noise of the engine. With a good quality ANR system the engine sound becomes a distant rumble, while voice communications are crystal clear. ANR headsets need an external power source to activate the electronics - a battery pack on the headset cable, batteries in the ear cup or a hard-wired plug on the panel.

When they first entered the market a set cost as much as a couple of hours in a Baron. Time and competition has brought the price down as more manufacturers have adopted various versions of the technology.

Swarovski Spotting Scopes

Passive noise reduction is an ear cup filled with a sound deadening material around the speaker and a strong seal that is clamped around the ears by the headband.

They nearly all come with gel filled ear seals that mould to the side of the head creating a better seal and enhancing comfort.

The more expensive examples use hi-tech materials in both the ear cup shell and inside, to deaden the sound, but the theory remains the BOSE Aviation Headphones same.

The newer top-of-the-line headsets from most manufacturers also boast Bluetooth connectivity for mobile phone and portable music device connection in flight.

"Consistently, pilots look for clear audio, noise reduction and comfort. Depending on the pilot's priority, they may choose to trade-off one or more of these items for others," says Bose aviation business manager Robert Elborough.

"A common trade-off seen in traditional aviation headsets has been between comfort and noise reduction. If a pilot prefers to have more noise reduction, traditionally they have had to sacrifice comfort and use a product that many be bigger, bulkier, with more clamping force."

Bose has been a key player in the development of ANR in headset technology. In Robert's opinion, ANR is worth the extra cost.

"The typical response we hear from pilots is: 'I wish I had changed to an active headset sooner'. It is a very rare situation to hear from a pilot who has decided to go from an active headset to a passive headset." Technology changes in the cockpit are reflected in headset design.

"It is clear that headsets are doing more than they have ever done in the past. The trend over the past few years is moving toward more features. Cell phone connectivity and auxiliary audio inputs are widely accepted now as base features, while at the same time the standard for clear communication, comfort, and excellent noise reduction continues to rise," Robert says.

There are also options for microphones, though in the past five years most manufacturers have favored electret or condenser over dynamic mics.

Electret microphones are smaller and lighter than dynamic and the old carbon mics. They place a charged flexible diaphragm a small distance from a plate.

Speaking into the diaphragm changes the distance between it and the plate creating an electrical signal that the radio processes. These are more expensive but produce a much clearer sound.

A condenser microphone works in a similar way except that a capacitor with an external voltage takes the place of the permanently charged diaphragm. This is simplifying it greatly but both types produce excellent sound quality.

Dynamic microphones form a middle ground in terms of cost and sophistication. In these microphones, a coil of wire is connected to the diaphragm, which is in a strong magnetic field. Sound waves moving the diaphragm and coil generate an electrical signal that varies in voltage with the amplitude and frequency of the sound waves.

Because dynamic microphones use a magnetic field, they are susceptible to electromagnetic interference, which can garble transmissions.

In some cases, older intercoms can have problems matching the impedance between electret and dynamic microphones leading to degraded cockpit communications.

This isn't a problem on the newer aircraft coming on line at flying schools. If you plan on flying with a friend regularly after you get your licence it's a good idea to buy two of the same brand of headset to avoid this kind of problem.

The microphone is attached to an ear cup via either a wire boom with an adjustment in the middle and at the microphone, or a flexible boom that will bend to any position.

The disadvantage of a wire boom is that the microphone lead is exposed and could possibly be damaged. A flexible boom has the microphone wire sealed inside.

So enough about the technology. What's best for you? Darren Webb is a private pilot who flies around 60 hours a year in his 172S. He went through several headsets before settling on the Bose A20.

"My first headset was a Peltor while I was learning to fly. It was a nice unit but didn't quite keep the noise out as much as I liked. Then I bought a David Clarke 13.4, which I used for 10 years."

"It's as good as the day I bought it though I found after long trips the clamping force became tiresome. I couldn't fault the audio quality or how well it stood up to being abused a bit."

"But the Bose A20 is in another league entirely - light weight, superb ANR and crystal clear communications. Given what it costs me to fly, the investment in a good headset is a small part of the total commitment to aviation."

West Australian company Skysports Innovations is leading the way in innovation with an integrated ANR headset and wireless cockpit.

"We've developed this system from the ground up. It's taken a lot of work to create fully duplex wireless comms, as radio frequencies can be knocked off by external sources. An aircraft is an RF jungle," says Skysports Innovations marketing manager Gordon Marshall. "We use 2.4ghz frequency hopping technology that jumps around 1000 times per second."

The company produces two options - a base unit that is installed under the panel for two place RAA applications, or a module that plugs directly into the microphone and speaker plugs on any GA aircraft and is combined with the EQ1 headsets to provide wireless communication for as many seats as the aircraft has.

"In the future there isn't going to be much improvement in the ANR side of headsets. Our headsets are among the best in the world, with digital processing that is expanding the frequencies that can be cancelled, but the way forward is wireless digital."