Rocket Science – die Firma, die einen Kamin ruhig stellt
by Livia Gamper
Earphones with transparency mode let in some noise, allowing you to hear your surroundings. However, not all true wireless models do an equally good job of this. A company called Rocket Science has put five current models to the test for us and found out how safe their transparency modes are in road traffic.
The audio nerds have struck again: Rocket Science has analysed and measured the transparency modes of five current true wireless earphones. Transparency mode, which, depending on the manufacturer, is also known as ambient mode, allows you to hear the sounds around you even if you’ve got headphones on.
In the article linked below, you’ll find out what Rocket Science is and why the company is testing headphones for digitec.
Our test set-up involves five current true wireless earphones, all of which are popular purchases on our site and are currently available for delivery. The Sony LinkBuds were used as a reference model because the hole built into their design gives them a natural transparency mode.
Here are the other models we tested:
Jabra Elite 85t
ANC, 5.50 h, Wireless, True Wireless
Samsung Galaxy Buds Pro
ANC, 5 h, Wireless, True Wireless
ANC, 12 h, Wireless, True Wireless
Luca Zimmermann from Rocket Science put five pairs of earphones to the test. Here’s the set-up he used: a small tube serves as an artificial ear and connects the recording microphone to the earphones being tested. A speaker plays white noise – constant sound covering all frequency bands. This noise hits the earphones first, then the microphone. The microphone measures how much sound gets through the headphones.
Luca left all of the transparency modes in default for the test. In other words, he didn’t alter the settings in any of the earphones’ apps. The tests were carried out without music, as the type and volume of music would’ve had too great an influence on the results. It would’ve taken an enormous effort to normalise the differing results between earphones. After recording the results, Luca also checked out the safety of transparency mode in road traffic.
The test readings are represented visually here. The Y-axis of the graph below shows the decibels with Z-weighting, while the X-axis represents the frequency from about 50 to 5,000 hertz. All of the curves measured by Luca drop off at about 5 kHz, since the earplug passively blocks out any sound above this level. The perfect transparency is indicated by the 0 dB(Z) line, which also matches up with the light blue line of the Sony LinkBuds. It’s precisely why these earphones have a hole incorporated into their design.
If you click on the graph, you’ll be able to see a larger version. To establish a ranking for the earphones, Luca calculated the average deviation from the ideal 0-dB(Z) line. The earphones with the lowest deviation received the best ratings. Here’s the ranking that came out of the process:
The first three sets of earphones all have an almost identical deviation. It’s curious that Sony is in last place with the most expensive earphones, the WF-1000XM4. Still, with the LinkBuds as the reference model, they’re also currently the leading manufacturer in this field.
However, Luca also clarifies that the average deviation from the 0 dB(Z) line is a pretty arbitrary measure. That’s down to it penalising the Sony WF-1000XM4, for example, for weakening at low frequencies – deviation can improve or worsen the ability to distinguish sound depending on the situation. Take the WF-1000XM4, for example. On a plane, the roar of the engine is blocked out and you’re better placed to chat to the person next to you. In traffic, however, this noise cancelling effect is problematic: you’re far less able to make out the rumble of a Harley. The Samsung Galaxy Buds Pro are also suboptimal in this regard: they reduce low sounds of up to 500 Hz too.
The AirPods Pro show a very flat line up to 1 kHz and then amplify the signal up until the 4 kHz mark. This is perfect for being able to make out the spoken word, which falls somewhere within this range. So, it stands to reason that most of the earphones tested strengthen the signal in this area. The AirPods Pro are particularly well equipped to stay in your ears during conversation – social faux pas aside.
In contrast to the AirPods Pro, the Jabra Elite 85t pair peak at around 1.6 kHz and then plummet. This means the sound is quite tinny and high frequencies are blocked out – these earphones show the fastest and most pronounced drop when faced with conversation.
The Nothing Ear (1) set has one of the lowest deviations. Interestingly, from the 750 Hz mark, its line takes almost the same course as the Samsung Galaxy Buds Pro, albeit a few decibels lower. This means the Nothing Ear (1) set does considerably better at lower frequencies, making it more suitable for when you’re out on the roads. Mind you, it isn’t great when it comes to speech intelligibility in the upper Herz range.
We’ve used an equaliser to recreate the curves and set them to the sounds of white noise and road traffic. That way, you’ll be able to hear for yourself how each of the devices sound in transparency mode. Rather than taking original recordings, we’ve used recreated audio samples.
During the test, Luca found that earphones which amplify the signal between 2 and 4 kHz have a noise floor. He heard that most clearly with the Samsung Galaxy Buds Pro, the Sony WF-1000XM4 and the Apple AirPods Pro sets. With this in mind, the top spot was reserved for the Nothing Ear (1) set, which doesn’t deviate much from the 0 dB(Z) line, although it doesn’t have much audible noise.
The measurements showed the Sony WF-1000XM4 and the Samsung Galaxy Buds Pro to be unsuitable for use in traffic due to the fact they mask low frequencies. But that’s not the only fly in the ointment. After all, when you’re out on the road, you need to be able to recognise where a sound is coming from. Locating sounds coming from the front or rear becomes more difficult when the ear canal is blocked by earphones.
That’s why Luca asked five volunteers to try out each pair of earphones. To do this, he set up two loudspeakers and played 20 different clapping sounds at random intervals in front of and behind the volunteers. Luca chose different claps so that the volunteers wouldn’t look for and memorise patterns. Otherwise, if they’d started to recognise one style of clapping, it’d be easier to determine whether the sound was coming from the front or the rear.
The results of this experiment are sobering. For a quarter of the clapping sounds, the participants weren’t able to tell whether the sound was coming from the front or the rear. So it’s fair to say that the earphones impair the ability to localise sound – transparency mode or not. Only Sony’s LinkBuds allowed every volunteer to correctly identify where every sound was coming from. Thanks to their open design complete with hole, they keep the ear sufficiently free to do so.
On the road, this deterioration in ability to perceive sound can have fatal consequences. Being unable to hear if a tram is approaching from the front or the rear rarely ends well. Locating sounds coming from the left or right, on the other hand, was a piece of cake for every test pair of earphones. That’s all because the delays for the left and right ear are identical.
If you’re wearing earbuds while riding a bike, this difficulty honing in on a sound is compounded by the wind. The wind noise can drown out other sounds coming from around you. Which is why Luca used a wind machine to see how the earphones coped with wind noise. No wind noise was present in Sony’s LinkBuds, while low to moderate wind noise was noted in the Nothing Ear (1), AirPods Pro, and Galaxy Buds Pro sets.
To top things off, Luca tested the latencies in transparency mode, as this posed an issue in previous versions of the earphones. However, all of the pairs being tested stayed below a delay of 0.6 ms, which is inaudible to the human ear.
The results say that if you want the perfect transparency mode, you have to go for the Sony LinkBuds. As a result of their design, background noises enter your ear exactly as they are. That said, this does give the earphones one disadvantage: every noise is audible. However, they’re the only earphones in the test that are relatively safe for use in traffic, since they allow you to correctly pinpoint any sound. Of course, it also depends on how loud you’re playing your music. If the bass is making your ears wobble and drowning everything out, the open design won’t do much good.
If you want to use earphones with passive or even active noise cancellation, only using transparency mode in certain situations, then you should opt for a different set. When it comes to transparency mode, Luca recommends the Nothing Ear (1) and the AirPods Pro, which are particularly good at letting voices through. This test didn’t look at audio quality, call quality or other features of the earphones.
We’ll continue to collaborate with Rocket Science. If there’s anything you’d like to know and want the audio nerds to measure, post it in the comments. Luca might have a look at your idea next.
Testing devices and gadgets is my thing. Some experiments lead to interesting insights, others to demolished phones. I’m hooked on series and can’t imagine life without Netflix. In summer, you’ll find me soaking up the sun by the lake or at a music festival.