Pilots may not realize it, but aside from the instruments, the most utilized cockpit item is the headset. Think about your last flight; everything that was communicated to or from your aircraft went through your headset. Consider the safety implications of that simple fact, and you can see why purchasing the right headset for yourself is critical. The encouraging news about headsets is that cost isn't directly related to effectiveness. While a $1,000 headset might be ideal for one cockpit, another might be more suited to a $200 headset. The key to selecting the right headset is to examine your own mission profile and applying the headset that best matches that profile.
We're in an age of unprecedented selection and features in headsets. Never before have we had so many choices at such low prices. The technology available today in ANR headsets and in condenser microphones was once the domain of high-end recording studios and wealthy audiophiles. Today, you can spend less than $100, and get better noise protection and audio fidelity (the quality of sound) than you would have 30 years ago for five times the price.
Several studies have concluded that hearing is second only to vision as a sensory mechanism to obtain critical information during the operation of an aircraft. Your sense of hearing makes it possible to perceive, process and identify the varied sounds affecting your aircraft. The FAA has spent much time and money researching noise in the cockpit in an effort to reduce the damage that comes from flying aircraft without hearing protection. Before we examine the current trends and technology advances in headsets, it's important to address the functions of aviation headsets and how they relate to hearing damage.
Hearing And Noise 101
Without going into excessive medical detail, humans "hear" sounds—which are waves of energy—as they're collected by the external ear from various sources. These waves travel into the ear canal and cause the eardrum to vibrate. This vibration is transmitted mechanically to the cochlea, which causes a pressure wave in the fluid inside the cochlea. That fluid moves minute hair-like receptors that line the walls of the cochlea (called "stereo cilia"), similar to how the wind moves a field of wheat. The movement of those tiny sensors produces an electrical signal that's transmitted to the brain via the auditory nerve. The brain identifies that signal as a particular kind of sound.
All sounds have three distinct qualities: frequency, intensity and duration. Frequency is the number of oscillations per second in a sound wave; frequency is also related to the "pitch" of a sound. High-pitched sounds possess a high number of wave oscillations per second. Frequency is measured in hertz (Hz). Intensity is the apparent "loudness" or volume of a sound and is measured in decibels (dB). Lastly, duration is the length of time a sound wave is active for. Hearing damage is a function of all three sound qualities.
Aviation Noise Sources
In an aircraft cockpit, most noise comes from the engine, exhaust, propeller and the ambient air flowing over the fuselage and control surfaces. The engine and exhaust sounds account for much of the noise and are concentrated in the low-frequency range of 100-150 Hz. In an open cockpit, noise comes mostly from high-frequency airflow on the aircraft and pilot's head.
OSHA (Occupational Safety and Health administration) has developed some specific hearing-loss figures and guidelines. They show that hearing damage starts when you're exposed to sounds with intensity levels of 90 dB or above, depending on the duration of the exposure. If exposed to 90 dB for eight hours or more, permanent hearing loss begins. To demonstrate the effect of duration vs. intensity, exposure to noise at 115 dB results in permanent hearing damage in just 15 minutes. The problem is that FAA and NASA noise studies show that our average general aviation cockpits routinely expose us to noise in the 100-110 dB range, especially in older aircraft. That's where headsets come in.
Headsets To The Rescue
Until the late 1970s, few people in general aviation wore headsets. Today, almost all of us do, and we all should. Even a cheapie headset decreases noise exposure by a good 15 dB, and those two-dollar wax-impregnated moldable foam earplugs designed for industrial and shooting use offer up to 35 dB of noise protection! You can see that even in a warbird generating 120 dB of noise (like a P-51 Mustang), just about any headset will bring the noise to manageable levels, at least for short durations. Combine a good headset that offers 25 dB or more of attenuation with foam earplugs, and you've got the best combination available.
Headsets come with either passive or active noise reduction. Passive ("PNR") headsets block noise using mechanical means: the ear cup, clamping pressure, ear seals and cup shape. Active noise reduction ("ANR") uses a technology developed in the '50s to sample the sound of the environment then block it using the same frequency as the offending noise, but "inverted." Think of it as blocking a sound with its identical-but-opposite "anti-sound."
How To Choose
Headset choices today range in price from $89 to over $1,000, with everything in between. The number of headsets on the market is staggering, and several manufacturers have come and gone in recent years. The best way to choose the right headset for yourself is to avoid the marketing hype and make your own evaluation. Modern retailers almost universally offer money-back guarantees, and aviation trade shows always feature major headset vendors.
Having tried literally hundreds of headsets myself in both my aviation and musical careers, my best advice to new pilots is to get the cheapest headset to start because you don't know what you don't know. It took me a good 30 to 40 hours of flying before I even thought of my headset or what I desired in one. I know people who plunked down big money for a whiz-bang ANR headset and ended up regretting it because their environment wasn't suited to that headset. And price is more about brand names, marketing and reputation. While I know plenty of pilots who swear by their $1,000 headsets, my favorite headset to date is a $200 passive unit that I "hot-rodded" with $100 worth of accessories to create the perfect open-cockpit setup. It's not what I'd use in a business jet, but for my environment, it's right, and that's the key.
ANR is perfect for cockpit environments that don't change much. Most jets and turboprops, technically advanced GA airplanes like Cirrus, Diamond and the like, are tailor-made for ANR headsets. Even the Beechcraft, Cessna and Piper line work well with ANR. But for demanding environments like open cockpits, warbirds, seaplanes and backcountry flying, PNR should be looked at carefully. Also, manufacturer attenuation numbers are almost meaningless. More useful are attenuation curves that show the headset's performance across many frequencies. Most manufacturers are reluctant to give these out. That's why "try before you buy" is a must.
If you experience discomfort with over-the-ear headsets because of clamping, you should give serious consideration to in-ear headsets. These typically weigh in at around an ounce and are so comfortable you'll forget you're wearing them. They seal in the ear and provide audiophile sound quality. My favorite headset for closed cockpits is an in-ear model I own. I love that the sound goes directly into my ear, allowing me to turn the whole intercom system down. And the comfort is unbeatable. Both Quiet Technologies and Clarity Aloft are companies that offer in-ear headsets. Other companies like Lightspeed were offering in-ear models, but no longer do. In-ear headsets are a revelation for many pilots and are worth a look.
There's a lot going on in the aviation headset world. First off, pilots have gone crazy for the GoPro series of POV (point- of-view) cameras. That relates to headsets, because pilots have thus far been unable to capture their cockpit audio without a lot of extra gear. Pilot Communications USA has come to the rescue with a line of recording adapters that allow pilots to send an audio feed directly from their headset to their camera, smartphone, or digital sound recorder, capturing ATC communication and intercom conversation. Pilot USA has been so successful with these and other adapters that they have become the world's largest manufacturer of headset adapters. "We can connect just about anything to anything," says company Vice President, Abram Akradi.
Along the same lines, Bluetooth wireless technology has overtaken the communications world, and Pilot Communications USA has developed their "BluLink" unit to adapt it to aviation. BluLink is a portable unit that allows integration of Bluetooth music and cell phone communication to any passive or ANR headset. It allows wireless communication with your Bluetooth-enabled cell phone or music player.
Small and light is the trend in headsets, and David Clark debuted their "Pro-X" ANR unit this year. Combining retro design with excellent performance, the Pro-X sits on the ear instead of around it. Not quite an in-ear headset, but not a traditional "clamping" headset, the Pro-X is bridging the gap between those two headset types and is one of the most comfortable headsets around.
Intelligent ANR came to aviation with Sennheiser's Digital S1 headset. It answers the dilemma of ANR headsets that only block a narrow band of frequencies. The S1 allows the pilot to push a button on the headset, sampling the surrounding environment. The adaptive S1 then counteracts the incoming frequencies with a tailor-made frequency response. Adaptive ANR is like having multiple headsets for different phases of flight.
"Hot-rodding" appears to be a growing trend, and users customize their headsets with after-market upgrades. Oregon Aero makes a popular "Hush kit" to improve attenuation on any headset, while Headsets, Inc., makes an innovate ANR kit to retrofit passive headsets with remarkable active noise reduction. Pilot Communications continues to market their excellent, high-performance PA9-EHN microphone for high-noise environments, as other manufacturers begin to focus on microphone performance. And that's just a small sampling of what's available in aftermarket enhancements.
The last trend we're seeing is the proliferation of ultra-low-cost headsets. While the market expands at the high end of the headset spectrum, more and more buyers are opting for low price coupled with great performance. Newcomers like BRG Precision Products, with their $89 passive headset, are appealing to a growing market. They, like others, offer a money-back guarantee to allow pilots to try their wares. With impressive attenuation numbers, companies like BRG, DRE Communications, RuggedAir, Pilot USA and Softcomm are all selling good-quality passive headsets for around $100. It's hard not to love these, and I've found almost all of them rival their expensive cousins. Any pilot in the market for a headset should give these a look.
The last thing to remember is that your friend's favorite headset probably won't be yours. Headsets are so different that personal preference is a major part of your headset-buying decision. Your headset will become like your favorite pair of jeans or a favorite t-shirt. My own headset has logged so many hours with me that I consider it an intimate part of my aviation life. Think about that the next time you're headset shopping. In the case of headsets, hearing, wearing and seeing is believing.