Tuesday, December 16, 2008
Today, aviation headsets sport more features than ever before. Use this guide to navigate your way through the headset jungle.
|Ask any two pilots what the best headset is and you’ll get two distinct answers, each with solid claims to back it up. There are scores of headsets on the market, and the different features of each model make choosing the correct headset a quagmire of myth, hearsay and fact.|
|Lightspeed Zulu |
Ask any two pilots what the best headset is and you’ll get two distinct answers, each with solid claims to back it up. There are scores of headsets on the market, and the different features of each model make choosing the correct headset a quagmire of myth, hearsay and fact.
The humble headset is the first piece of flying gear a student will be exposed to. It might also be the first piece of professional gear a pilot will purchase. The price of a good headset assures that it’s not a trivial purchase, made on a whim. Purchasing a headset, though, can be confusing and complicated. We’ve done some research into the factors that might influence your purchase, and present this buyer’s guide to aviation headsets.
Passive Vs. Active
Pilot headsets come in two basic flavors: active noise reduction (ANR) and passive noise reduction (PNR). In an ANR headset, a tiny microphone inside the ear cup picks up the noise around it. The noise sample is passed to electronics that produce an exact opposite “mirror image” of the sound. Tiny speakers generate the new sound back out to the ear cups. Because the generated sound is an “anti-sound” to the original noise, they meet and cancel each other out. The result is silence.
|Beyerdynamic HS 300 |
ANR only affects certain low frequencies, so normal speech, changes in engine sound and airflow over the fuselage are all easily detected. Because ANR headsets rely on electronics to block damaging noise, they don’t need to clamp tightly to your head and can be lighter and smaller than other headsets.
PNR is more like soundproofing your garage when you’re in a band: it blocks damaging noise by stopping it with barriers. These headsets rely on clamping mechanisms to keep the ear cups sealed against the wearer’s head. The cups completely cover the ears, and dense foam inside the ear cups absorbs sound while gel ear seals conform around the ear to stop sound waves.
Telex Stratus 50
|Advances in different technologies have yielded aviation headsets that rival music-production units, yet are small and lightweight. Microphone and speaker innovations provide unparalleled sound quality and intelligibility, increasing situational awareness. |
The headset’s basic job is to reduce (i.e., attenuate) harmful noise, and that ability is measured in both frequency range and number of decibels (dB). A headset rated at minus-24 dB at 100 Hz means it cuts noise in only that frequency by 24 decibels. Cockpit noise that’s most damaging to human hearing is in the low-frequency band of around 40 to 250 Hz, while human speech is up around 400 to 4,000 Hz.
ANR headsets attenuate mostly in the low-frequency range, but aren’t always effective in the speech range. Consumers might see noise reduction advertised as 26 dB, but that’s only in those low frequencies. Reduction elsewhere might only be 5 dB. Though ANR is an amazing technology, it doesn’t always beat out passive reduction.
Passive headsets block frequencies across a broader range and may offer higher noise reduction than ANR headsets, especially in speech frequencies. PNR does come at price because PNR headsets clamp tighter than their ANR counterparts and are usually heavier and seal tighter around the ears, which can become uncomfortable over long periods of time.
Companies like JH Audio, Clarity Aloft and Quiet Technologies are making the drawbacks of passive headsets obsolete with new lines of featherweight headsets. They use custom-molded ear inserts to provide up to 45 dB of noise reduction using passive technology. In all cases, pilots should consult the attenuation curves available from each headset manufacturer.
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