For fifty quid, you can buy a good set of ear canal headphones, which reduce external noise pretty well. My opinion is that this item offers similar noise isolation, whilst going the extra mile with a useful dollop of cancellation.
The item comes with three different sizes of rubber ear insert. The smallest of the three are an excellent fit for my ears. Noise reduction, without turning on the device, is massive compared to over the ear headphone designs. I find them easy to wear as long as they're pushed into the ears well.
Inserting the supplied battery and turning on the unit, without any audio, clearly suppresses further sound. In a quiet office, it's noticeable. On a train, with lots of constant, thrumming sounds, it's very effective. It is less effective with high-pitched, sporadic sounds, such as a baby's screams...
Without suppression, and with music, they sound very good indeed. Flicking on the suppression increases the sensation of both volume and bass, meaning that even in a library I would prefer to use the technology.
On the move, in the real world, the additional comfort of being able to listen at lower volume levels, can not be underestimated. It also has to be much better for your long term hearing prospects!
There is one irritation. The cable between the ears and the unit with the battery inside, is ridiculously short. What on earth were they thinking? I can only assume that the designer was a very short human. I'm 5'11 and it's too short to clip to my belt. I clipped it to my shirt instead, which works ok. At least the cable from the unit to the 3.5mm jack is long enough to allow you the option of stowing your player in any pocket you choose.
To be honest though, I will probably reserve these headphones for trips, so the extra bulk and inconvenience of the battery unit cable, is irrelevant. Being too isolated from external noise can be dangerous on a bike or on the street, where you want to be able to hear a potential threat coming.
Creative EP-3NC Noise Cancelling Earphones with Travel Pouch and Adapter - Black