When was the last time you tested your audio system to see what decibel level you were listening at? Chances are the neighbors help keep your two-channel gear in check, but headphones can be cranked to volume levels that are both insanely loud and unsafe without anyone else knowing or complaining.
Do you find yourself gradually increasing the volume on your phone or DAP as you go through your workday?
Have you taken off your headphones with music playing and thought “Wow, I didn’t think it was that loud” with them hanging around your neck?
Most of us haven’t tested to know exactly what listening level our gear is producing and even those of us that know better sometimes cheat. The problem is that hearing damage is insidious as it doesn’t manifest itself until much later, so we generally think we got away with it.
There are headphones for children that limit the decibel level to prevent them from damaging their ears without knowing it, but somehow as adults we are just supposed to know and while most of us know that we can do long-term damage by standing on a shooting range or drag racetrack without hearing protection, few realize that average music listening sessions may be doing the same kind of damage.
I conducted an experiment just to see and asked a group of 10 people to listen to the same song at 4 different volume levels and tell me which was closest to the level they listen to while using their personal audio gear during the workday.
8 out of the 10 people in my impromptu survey picked a listening level that, if used for extended periods, is probably damaging their hearing, and two people chose a level that is capable of doing damage in as little as 30 minutes. The results were certainly alarming.
The guidelines state that continuous exposure to sound over 85 dB can damage hearing, 95 dB is acceptable if kept to periods of less than 50 minutes per day and anything over 120 dB can cause severe and immediate damage.
In my little experiment, most selected a level over 85 dB, one was over 95 dB and another was nearing 100 dB. When I showed them the values of each sample, none of the group realized they were listening at levels that could damage hearing. The question I kept hearing was “well how do I know if I don’t have fancy test equipment like you do?”
The answer is without testing you either rely on your gear to limit you to safe levels or you take the risk. This has become such an issue that in European Union, the EN 50332 standard specifies that devices have a limiter built-in and on by default. Adoption is slow to say the least as neither the USA, nor the Asian countries have similar requirements and with most DAPs (Digital Audio Players) being made in China, they have no requirement to obey the EU mandate.
I’ve used apps on Android and iOS devices to do this same thing to protect my children’s hearing with varying degrees of success. I found that some programs ignored the rules set, and other times the kid could go into settings and simply turn off the volume control by killing the app even though it required a password to turn if off through the interface. Hardware controls seem like the best option to be safe and to be sure it works.
Puro Sound Labs specializes in making headphones with volume limiting built-in with models for children and adults as well as models designed with gamers in mind. The model I was sent is the PuroPro; their current flagship. It ships in a wooden crate with a hard-shell carrying case, headphones, charging cable, and manual inside and is geared towards audiophiles.
The PuroPro limits output to 85 dB by default, but even Puro recognizes that some songs need to be cranked. The user has the option of raising that limit to 95 dB to enjoy “I Wanna be Sedated” and then return to the more sedate 85 dB for the rest of their playlist.
The PuroPro has a very familiar aesthetic with cups just barely larger than the ear, and an all-black aesthetic. Most of the construction is plastic with metal used in the headband for increased durability and protein leather used in the pads for added isolation.
They look a lot like the Sony 1000XM4 or Bose QC35 II and are similar in size, shape, and weight. Similarities to the Bose and Sony products continue inside the shell with Puro aiming to dislodge those two from the top spots in the noise cancelling headphone category – no small order.
The heart of the PuroPro is a 40mm dynamic driver with a nominal impedance of 32 Ohms and a sensitivity of 120 dB/mW. Wireless models don’t release these specifics very often about drivers as the designer has already accounted for those details in the design of the onboard amplifier.
It is nice to know these can be easily driven by a phone in wired mode in a pinch after the battery dies rather than be stranded with no music until the plane lands.
Pretty much all noise cancelling headphones trade some sound quality for noise reduction and the PuroPro is no different. It sounds best with the ANC turned off in quiet environments and trades some sparkle and detail retrieval for noise reduction with ANC enabled.
I found the PuroPro to be a V-shaped consumer friendly signature with enough detail to make it a pleasant listen and while I wouldn’t use them as my reference for monitoring, they were never intended for that market.
For travel, commuting, and office environments, they fit the bill quite nicely and I’d welcome them as my travel companion on my next trip abroad. I found the PuroPro sound quality to be equal to the Sony with ANC disabled and nearly as good with Deep ANC engaged.
The PuroPro sports an advanced active noise cancelling system with 4 mics used for measuring ambient noise around the user and a microprocessor-controlled mechanism for producing the adjustments needed.
ANC does limit sound quality a bit, but the tradeoff is very noticeable in loud environments. I found the general noise reduction mode (-15 dB) was good for general office and home use and eliminated things like vacuum cleaner noise quite well.
For really loud environments like lawn mowing (not condoning wearing headphones while mowing, only using as an example of noise level) or airline take-off the 32 dB deep noise cancelling mode offers even more filtering, and if enabled in my office environment, effectively created silence when music was not playing and delivered a nice clean portrayal of my chosen playlist when engaged.
Controls are straight forward with buttons on the bottom of the cup for adjusting volume, skipping to the next track, enabling ANC modes, and adjusting the volume limit. Charging is accomplished by a micro-USB port in the right earcup and once charged the PuroPro’s 750mAh battery is listed as providing up to 32 hours of listening time. My testing yielded an average of about 25 hours with ANC engaged which is still enough to fly to Australia and back without needing to find a charger.
Some will question the need for a volume limiting headphone, but for others it makes great sense. Especially those of us with children who may use our headphones during remote Zoom learning, car trips, and on airplanes.
But let’s look at the PuroPro as a wireless noise cancelling headphone and ignore the whole volume limiting thing for a minute. The PuroPro offers a mature sonic signature, very good noise cancelling, and solid battery life at a price point that is attractive compared to those other brands I mentioned earlier. Performance is on par with those other models as well and I’m not going to go deaf listening to them either.
For more information: $199 at purosound.com