I talked in #187 of the Aviation News Talk podcast about what you need to know about hearing loss, how hearing loss affects people, and the many ways that pilots and others can permanently damage their hearing. And now there is a new headset that not only helps prevent more hearing loss, but it also provides pilots with a custom sound profile…to compensate for hearing loss you already have. But probably the best feature is that the headset has a built-in carbon monoxide monitor that is always on when the headset is on. I love that because now I don’t have to remember to pull out and turn on my standalone CO monitor when I fly.
The headset is the new Lightspeed Delta Zulu. Lightspeed lent me a demo unit to evaluate, and here’s what I found when I flew with it.
First ANR or automatic noise reduction headsets were introduced about 25 years ago, so the technology is mature. Hence, there’s not a lot of improvement to be had in making headsets quieter, though Lightspeed says the noise reduction is a little better in the Delta Zulu than their prior headsets. So, since there’s not a lot of improvement to be gained in making headsets quieter, Lightspeed chose to add new functions to bring additional value to headset users. And I think they’ve made some savvy choices.
Built-in CO Monitor
First there’s the CO monitor. I talked in #90 of the Aviation News Talk podcast with Mooney pilot Dan Bass, who passed out due to an exhaust system leak that let CO into his cockpit. On his third flight of the day, Dan passed out during the climb with the autopilot on. And when his aircraft eventually ran out of gas, it descended at climb speed and crashed into a snowy field in Minnesota, where Dan woke up in the crashed airplane.
Although you can’t see, smell, or taste it, carbon monoxide can make you sick or kill you. The problem is severe enough that the FAA tasked Wichita State University to investigate the problem and solutions.
According to the report, “The FAA standard for CO in an aircraft cabin is no more than 50 ppm [parts per million]; however, there is currently no requirement to monitor for CO in the cabin.”
Wichita State found that “CO was detected on more than 90% of the flights monitored (either on the ground, in the air, or both), [but] the majority of CO events detected were less than 10 ppm…with a very small percentage [of flights] detected with levels above 50 ppm.”
Many pilots use a cardboard chemical patch detector that sticks to the instrument panel. These are inexpensive, less than $10, but have drawbacks. First, they don’t detect low levels of carbon monoxide. Tests show that they take a couple of minutes of exposure to high levels of carbon monoxide—in excess of 100 ppm—before turning color. They also need to be replaced every few months, so unless a pilot is diligent about changing them, he or she may get a false sense of security.
You should know that a single backfire, such as when you’re starting the engine, can damage an aircraft’s exhaust system sufficiently to let carbon monoxide into your cabin. So even if your plane is well maintained, and you’ve checked it for CO in the past, you’re only one backfire away from getting CO poisoning.
The new LightSpeed Delta Zulu headset has a built in CO monitor, and it gives you a voice alarm, through the headset, if it measures CO, above certain thresholds. Lightspeed has a new app for the headset, and in that app, you can set the sensitivity for two alerting levels. The default threshold for the caution alert is 50 ppm and for the Warning alert its 100 ppm. Those levels are higher than I would prefer, but in the app, I can set the caution threshold with a slider to any value between 10 and 50 ppm, and the warning threshold to anything between 51 and 100 ppm. The Caution alert message is repeated every 5 minutes, and you can also set how frequently you’d like to get the message from anywhere between 5 and 15 minutes. Typically in the past, using my handheld CO monitor, I sometimes find when an aircraft is first started, I’ll see readings of around 10 ppm, but normally in flight, it drops down to single digit levels.
Lightspeed has had a few dozen of these headsets out in the field during the past few months being tested by pilots, so there haven’t been a lot of flights with the headset. Even so, one of the testers reported a couple of weeks ago that he discovered a CO leak in the plane he was flying because he was wearing the Delta Zulu headset at the time.
The first day I flew with the headset, shortly after we started the engine, the headset said to me “5 ppm” or 5 parts per million. Later it said “6 ppm.” When we got in the air, I checked the app, and it showed we were at 0 ppm, and I didn’t get any other messages from the headset about the CO levels. BTW, the app does have a stats button, which takes you to a graph to view statistics, not just for your current flight, but for prior flights as well, showing the carbon monoxide levels. The graph also shows the cabin temperature.
Built-in Audio Equalizer
Having a headset with a built-in CO monitor would in itself be sufficient to make me want to buy the Delta Zulu. But it also has a built-in equalizer, that Lightspeed calls HearingEQity, that lets you customizes what you hear from the headset, to match any hearing loss you may have.
The way you calibrate the headset equalizer is similar to the way an audiologist would give you a hearing test, or would customize the frequency response for a hearing aid you might wear. Essentially, you go to a quiet room, put the headset on and turn it on, and then the app walks you through the test procedure. I did the setup in my bedroom, since its quiet. It probably took me 7 or 8 minutes, but I was taking a lot of time to do it carefully, and you certainly could do it in less time.
To set up the equalizer, turn on the headset, and pair your iPhone with the app. Then touch the equalizer tab at the bottom and then touch the Setup button. The app will then present a 125 Hz tone to one ear, and you’ll need to adjust the volume slider on the app until you just barely hear the tone. You then repeat that for 11 other tones, with the final one being at 12 kHz. That was the only tone I couldn’t hear, since it was such a high frequency, so I left the slider at the maximum volume. The app then runs through all 12 tones for your other ear.
When the setup was completed, the app presents a bar graph showing the amount of gain the Delta Zulu headset will add for each frequency band to attempt to give you normal hearing. My bar graph showed some hearing loss at low and the high frequencies, with mid-range tones being more normal.
When you’re done, the app plays a song you can listen to, and it lets you switch the HearingEQity equalizer on and off, so you can see the difference it makes. As I switched it on and off, I noticed that the song did sound richer, with HearingEQity turned on.
By the way, if you happen to already wear a hearing aid and you like to wear it under your headset when you fly, you can do that. When you Setup HearingEQity, just make sure that you’re wearing you hearing aid when you do the setup.
During my airplane flights, I wanted to see the difference with HearingEQity on and off, and there’s a button on the headset control box you can double push to turn HearingEQity on and off. What I found when listening to controllers was that their voices sounded richer and less tinny. So it actually made listening to the radio a little less irritating. I’m a CFI, and I often fly 4-5 hours or more per day, so anything that makes listening to the radio more pleasant is a welcome change.
Lightspeed Delta Zulu Batteries Swap Quickly
Batteries are often an issue with ANR headsets, but the Delta Zulu has a slick solution that lets you swap batteries much faster than other headsets I’ve seen. The control box, which is inline with the headset cords, has a rechargeable lithium-ion battery that snaps in and out in just a second. Lightspeed says the battery lasts about 30 hours when it’s fully charged. Plus, you can charge the battery in flight with the USB-A cable that Lightspeed provides. Just plug the cable that comes with the headset into a USB port in your aircraft or any portable battery pack. Lightspeed also provides a second battery pack that holds AA batteries. So that is a great backup if the rechargeable battery fails, and you don’t have a USB port for recharging the battery.
In the plane after turning the headset on and connecting to the Lightspeed app on my iPhone, I heard through the headset “battery charge full,” which was a comforting a message, as I hate running out of battery power when using an ANR headset.
Delta Zulu Accessory Cables
The headset also includes Bluetooth that enables cell phone connections and streaming of music from your phone or tablet in flight. You can also buy separate cables for connecting to 3.5mm and Lightning port devices if you’d like the additional reliability that a cable provides versus Bluetooth connections. I’ve used a cable like that for years on my existing Zulu 3 headset to stream Facebook Live videos when I’m at lower altitudes and can get cellular data in the plane. The benefit of the cable is that I can narrate the video in real time, and respond to people who are watching the video live.
You can also record everything you hear in the cockpit directly to the Lightspeed app. So it will record what you hear on the Comm radios and everything you say and hear over the intercom. I’ve used this many times in the past to record conversations, which I can then share with student pilots I’m flying with.
The Delta Zulu has an Auto shutoff, which saves batteries by turning your headset off after it hasn’t been used for about a minute. I know it works, as the headset turned off a few times as I was playing with it on my desk to learn its features.
Lightspeed Delta Zulu Plug Options
It can be ordered with any of the following connectors. The dual GA plugs, which are the most common headset connectors in GA aircraft, the LEMO connector which is a single round black connector found in many newer aircraft, or the U-174 helicopter connector. The headset also has a 7-year warranty.
I’ve been using Lightspeed headsets for about 25 years, and currently own three different models I’ve acquired over the years. Headsets are a very personal choice, because not everyone’s ears are the same, so what feels good to you… may not feel good to someone else. I initially started using Lightspeed headsets, because they didn’t hurt my ears… unlike a competitive model, which made my ears hurt a lot after wearing the headset for just an hour. That particular headset model has long since been replaced by a more comfortable model. Still, I’m sold on Lightspeed for several reasons. I love their tradeup program which helps me preserve the investment in my headset. I started with the Lightspeed 15, traded up to the 20 and later the 25, and then to the Zulu and then the Zulu 3. Getting hundreds of dollars back when you trade in your old headset feels really good. I’ve also had my Lightspeeds serviced a few times, and they’ve always gotten the headsets back to me quickly for no charge. And for years, I’ve been able to record everything I hear in my headset, including the radios and the intercom chatter, using the Lightspeed app on my iPhone.
The Delta Zulu headset sells for $1099, the Lightspeed Zulu 3 which I’ve been using for the last few years, sells for $899, and the Lightspeed Sierra sells for $699. These links take you directly to Lightspeed website, where you can order direct from the company. These are affiliate links, so if use them to go to the Lightspeed website and choose to buy a headset, Lightspeed will pay a small referral fee to support Aviation News Talk. The cost of the headset to you is same, regardless of whether you use these links or not.
Thanks for taking the time to read my review, and if you’re unfamiliar with the Aviation News Talk podcast, you can learn more about it at aviationnewstalk.com and you can find it by searching in any app you use to listen to podcasts.
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