The Nuraphone G2 headphones are radically different. They are almost purely wireless. The analogue cable is an optional extra. For Bluetooth it uses the next best thing after wire: aptX HD. (A Google Pixel 3 phone confirmed it was using this codec.) It should also be compatible with regular aptX. But with no mention of AAC, iPhones would fall back on the regular base-level Bluetooth stereo codec of SBC.

A full charge of the battery is good for 20 hours of use. There’s no on/off switch — they switch themselves on and off according to whether or not they’re on your head. When placed on, they greet you by name and announce their level of charge.

These are over-ear headphones. And they’re in-ear headphones. Yes, both. There are two drivers in each earcup. One is for bass and it works inside the earcup. But also, there are also soft eartips, loosely held by a rubbery diaphragm. They in a position so that when you don the headphones, they are held placed against the openings of your ears. Inside them are full-range earphone drivers.

That bass driver has a separate level control in the app, called ‘Immersion’. This is kind of like having a subwoofer to support bookshelf speakers.

Furthermore the headphones process the sound to match each user’s hearing profile. They set the profiles up automatically using a property of the ears, called ‘otoacoustic emissions’. When the working parts of one’s ears are stimulated by sound, they respond with their own vibrations. These can tell experts a lot about the functioning of the ears and are used to test the hearing of newborns.

The app on your connected phone — iOS or Android — runs you through set-up. The app make a gentle noise through them for a minute or so and measures the results. It then creates the profile. You can have three named profiles in the app, and the voice in the headphones refers to you by the name.

The ‘G2’ here doesn’t indicate a second model; so far there has been only one Nuraphone. That G2 marks the firmware, which added active noise cancellation.

You can use these headphones with an optional analogue cable (not included). If you do, they will use the currently chosen profile along with the level of ‘Immersion’ last used. You’ll have to pull the cable and reconnect via Bluetooth to your smart phone to change it.

Everything is controlled by the app, though there are four physical controls. A touch-sensitive ‘button’ on each cup can be single or double tapped, and you can assign all the usual functions to those. You can switch noise cancellation on or off in the app (but can’t assign it to one of the buttons). And you can switch on sound pass-through, which uses the microphones, provided for the hands-free phone functions, to pass through outside sounds so you can hear what’s going on around you.

Because they are so unusual, I’ve spent a big chunk of this review just describing these headphones. So the question is: how do they sound? And the fact is, I can’t tell you!

Once you’ve set up a profile (which is pleasingly displayed as a pink-purple splodge, mine shown right), you can listen using that profile, or you can switch to the ‘Neutral’ mode. I can comment on the sound of the ‘Neutral’ mode because it’s the same for everyone. It sounds pretty poor. It’s kind of flat, a bit midrangy, closed in, limiting. It’s kind of what you’d expect from a pair of indifferent headphones. Cheap ones, even.

So by comparison, switching to my ‘Personalised’ mode sounded simply wonderful. The sound opened up. The bass and treble lifted to provide a much better tonal balance. That ‘veil’ metaphorically used by some many hi-fi reviewers had been especially thick, more like a hessian sack. And it was lifted to reveal something still in the realm of ‘adequate’, but which sounded wonderful by comparison.

Cynical individual that I am, I wanted to check that it wasn’t just changing settings from a preset ‘poor’ to a preset ‘good’. We set my wife up with a profile. She enjoyed the sound delivered by that profile. I detested the sound delivered by her profile. So the whole set-up is certainly doing something individual for each of us.

The tonal balance with my profile in place was pretty good. But remember that the ‘Immersion’ level — the ‘subwoofer’ level — is set manually. I set it to provide the deep tones underpinning the bass drum and cannon on the Telarc 1812. But that proved to leave it a touch too high for Laura Marling. In the end I settled on a setting with the slider at about 15%.

The performance highlight was with the Liszt piano. The headphones delivered very realistic sound. There was no unusual sibilance or other treble anomalies on the other material.

Levels were adequate even on the 1812, but the volume control was very coarsely grained. Perhaps it was the phone, but I found that the volume seemed to jump by something like six decibels on each of the two highest positions.

Two final notes. First, that outer driver or subwoofer has some oomph. If you turn it up more than about halfway you’ll be finding the whole bodies of the headphones vibrating from time to time. Push it harder on something like the Eminem, and you’re in another world, not quite like any other acoustic experience I’ve had.

Second... ‘neutral’? I’ve just been through very close listening to six other pair of headphones, none of which does anything at all to the signal, other than reproduce it. Their drivers have all ranged from quite good to extremely good. And all of them sounded to my ears on a scale from enjoyable to superb.

So, why does ‘Neutral’ sound so lousy on the Nuraphone headphones? Is ‘Neutral’ programmed to make it seem poor? Or is it a clean signal, and the basic drivers are themselves rather ho-hum?

I can’t answer that. I’d just suggest that the highest quality sound — even at $499 — might be found elsewhere.

However, if you’re after Bluetooth, active noise reduction and don’t mind fairly bulky headphones, then these are worth checking out. I found that I preferred their sound more than that from a certain famous brand of noise-reducing headphones that I use routinely while travelling.

One thing with analogue use: the Nuraphone headphones have the weirdest impedance curve. Use only with low impedance devices or you’ll get no treble.

Nuraphone G2
Price: $499

+ Bluetooth connectivity with aptX HD support
+ Good sound quality for this market segment
+ Active noise reduction

– No analogue cable included
– Weird impedance characteristic with optional analogue cable

Drivers: dynamic, two-way
Fequency response: Not stated
Nominal impedance: Not stated
Sensitivity: Not stated
Weight: 329g
Contact: Nura Operations
Telephone: Live chat only, no telephone available
Web: www.nuraphone.com