The Telex line of lightweight headsets, both with and without ANR, is very popular—even dominant—in the relatively quiet cockpits of large corporate and commercial jets. Many new light jets are delivered with two Telex headsets as standard equipment.
Unfortunately, this leads many first-time jet pilots to believe the headsets are adequate for regular use in light jet cockpits. We have found this not to be the case. As the flight progresses and hearing fatigue sets in, it’s usually a matter of when, not if, pilots start missing radio calls if they’re using lightweight, on-the-ear headsets. The common fix is to get full-cup, over-the-ear headsets common in turboprops and pistons.
Telex makes a good effort with the Ascend to cut the noise without cups using ANR to tackle nearly all the noise reduction. As a bonus, the ANR takes its power directly from the intercom system, eliminating the need for batteries—a trick Telex uses on several headsets. But in our opinion, this effort falls short.
Part of the reason may be the noise frequencies dominating the cockpit of a jet. As opposed to the low-frequency engine and propeller noise of piston and turboprop aircraft, the noise in small jet cockpits tends to be dominated by higher frequency sound. The three worst offenders are windshield bleed air (for aircraft such as the CJ1-3 lacking an electrically heated windshield), “wind” noise increasing as a function of indicated airspeed and environmental system (duct and fan) noise.
Flight Tests
We tested the headset in two aircraft, a CJ3 and a Phenom 300. In the CJ3 in particular, the need for windshield bleed air and defog fan activation in descent created noise the Ascend did not adequately mask. Turning the ANR off and on seemed to only shift the frequency of background white noise, without causing a noticeable decrease in total sound. As a result, ATC transmissions were much harder to understand, as compared to the Bose X used as a reference.
The headset is exceptionally light, with very low clamping force. There were no noticeable pressure points on top of the head, even after hours of use. The earpieces swivel easily to keep the speakers flat against the head with minimal ear pressure.
Despite this, the headset seemed less suitable for prolonged use with sunglasses than an over-the-ear type. As the Ascend applies pressure directly to the ear, over time our sunglass temples pinched between our ears and skull. With an over-the-ear cup, pressure is applied surrounding the ear, so the temples are only contacting small areas in front of the ear, distinctly more comfortable.
While it may just be personal preference, the mic boom felt too short, putting the mic off to the side of the wearer’s mouth. This may have been the cause of what we felt was muddy sound both in sidetone and over the intercom, as reported by the copilot.
The Ascend also lacks its own volume control. This reduces the ability to set differing volumes between pilots. The aircraft audio panel provides some authority to do so, but having a headset-specific control is useful in providing the most volume range between seats. This ability was missed when flying with the Ascend.
The Ascend could be a suitable headset in a larger jet with minimal wind noise and a quiet environmental system. The lack of need for battery power and lightweight design would make for a comfortable, easy-to-manage package. Unfortunately, in the noisier cockpits of in-production light jets, we don’t think it’s the best choice.
Neil Singer is a mentor pilot in light jets and a freelance aviation writer.
