Test flight: The game-changing Delta Zulu headset

This story was updated with new information on Nov. 9, 2022.

It’s a low tone. More vibration than sound. Insistent, but not annoying.

I slide my index finger across the face of my iPhone and the tone gets lower… lower… lower… and when I can barely hear it I select Next. A new tone starts. Slightly higher now. More Morse Code than vibration.

I’m taking a hearing test in the comfort of my home. A test administered by a Lightspeed Delta Zulu headset.

The 12 tones, ranging from 125 Hz to 12,000 Hz — first in the left ear, and then in the right — gather data for what Lightspeed calls HearingEQity, a new twist on active noise reduction or ANR.

In addition to blocking unhealthy noise, this next-gen Lightspeed headset is designed to actually boost sound levels you can’t hear well, a possible game-changer for an aging U.S. pilot population.

I have hearing loss myself — worse on the high end — and sure enough, as the test got into the higher ranges I found that, rather than reduce the volume to the lowest detectable level, I had to turn the volume up to even hear the tones at all.

The test complete, I’m given a clip of music to listen to, and I can toggle the HearingEQity on and off to hear the difference. To be honest, the difference was subtle at best, but the music did come across somewhat richer with HEQ on and better balanced between my ears with no differential volume adjustment.

What music, you ask? The William Tell Overture, of course.

Now it’s time to fly the Delta Zulu.

Dispatch from east of Santa Rosa Route 66 Airport (KSXU) in New Mexico, descending through 7,200 feet MSL: The canary chirps in my ear. Actually it speaks in a pleasing low-key male voice, calmly saying, “Carbon monoxide unsafe level.”

It’s a Delta-Z Kanari Smart Alert — as in the proverbial canary in the coal mine — and this is the second fascinating feature of the new Delta Zulu. The headset sniffs the cabin air and alerts you if it detects carbon monoxide. But the level wasn’t really unsafe. I set the detector to the lowest possible level of 10 ppm to trigger an alert.

The headset’s CO detector is set up through an iOS app that also displays the current CO level, and can show a trend line. This trend line is supposed to be archived for comparison purposes from flight to flight, but my version of the app (a beta) crashed after every flight — better it than me — and in doing so lost the data each and every time.

But it does work in flight, and the NTSB, which has been on a carbon monoxide crusade for years, will probably give Lightspeed an award. This feature will no doubt save lives.

In my flights with the Delta Zulu, I did notice that the headset’s CO readings were significantly and consistently lower than the readings from my Sensorcon Av8. But bear in mind that we’re talking very small “background” levels here, and the headset is detecting the air around my head, the air I was breathing, while my portable hangs from a side panel below my shoulder.

On the head

My loaner headset arrived with its own fog bank in the box — a full week of the worst weather I’ve seen in years — so I didn’t get to fly with it as much as I planned to, but I did get in four flights, including an all-day cross country. And the first thing I noticed about the headset was that I didn’t notice it.

Even after a grueling, turbulent, three-state flight, the headset remained comfortable.

The notched headpad allowed me to wear a hat with a button top without feeling like a nail was being driven into my skull. The earcups gave my ears plenty of room, and the seals were comfortable and adapted quickly to my standard eyeglasses.

Controller

The Delta Zulu’s controller features a new form factor, with the wires to both the headset and to the panel going in the same end, allowing the controller to slide more easily into a map pocket, at least in theory.

However, the plug-into-the-airplane cord is short, and even in my cramped cockpit, wasn’t long enough to reach from the audio jacks in the center of my panel to the map pocket on the side wall. The cord was also too short to just let the controller rest on the floor.

Lightspeed officials note that while the standard configuration will be fine in most aircraft, the company does offer longer cable options. When ordering the headset, a pilot can specify a longer upper or lower cable (or both). An extension of 12 inches for both options can be implemented and will be modified at no charge, officials added.

Power

The headset comes with two battery packs, one for AA batteries, the other a rechargeable lithium-ion battery which has to be attached to the headset to charge.

I opted for the AA option so I could have spares if needed — and I needed spares.

I found the battery life of the AA batteries in the Delta Zulu shorter than the battery life of a Zulu 3, the company’s predecessor headset.

However, I should note I did run it using the heavy Bluetooth for the CO monitoring in the headset’s app and Bluetooth is notorious for gobbling batteries.

Lightspeed officials recommend using the lithium-ion battery as the primary battery pack because it has 30 hours of life on a single charge, and it can be charged while flying — either from a charging brick or a panel mounted USB charger.

“The AA pack is great as a back-up,” say Lightspeed officials, who noted that the company’s lab and field testing shows the headset gets 15 to 20 hours of life on the two AA batteries.

Sound Quality

I’ve been using passive headsets lately, and the ambient noise level with the ANR is remarkably lower in flight, but not so extreme that you can’t hear changes in engine noise that might signal trouble.

Radio calls were amazingly crisp and clear, as was intercom chat in flight. Music via Bluetooth sounded fantastic, and I appreciated the sweet way the music faded out smoothly for radio calls, and then gradually faded back in. Of course, via Bluetooth, you can make or receive phone calls.

But perhaps of greatest interest, I found that my post-flight tinnitus was significantly reduced with the headset, compared to other ANR or passive headsets.

That, for me, is the biggest game changer in a headset that’s posed to change a whole lot of games.

The headset is available now at a suggested retail price of $1,099. Find out more at LightspeedAviation.com.