I have a pair of Sony noise cancelling in ear phones which are pretty effective.
I forgot to take them with on my last flight, so bought these with similar expectations (since the configuration is all but identical).
Nope - nowhere near the "90%" claimed. I'd say most of the noise suppression came from having my ears blocked up.

I fly a lot for work so I decided I should purchase a pair of noise cancelling headphones. I chose not to go with the over ear headphones because I usually like leaning my head on something which then vibrates through the headphones and defeats the purpose. These in-earphones are perfect for what I wanted. It probably blocks out about 70% of noise and the form comply tips are really nice on the ears. Only downside, the battery pack and control unit is awkwardly placed along the length of the cable.

Copped these for $79 and they are my first pair of noise cancelling earphones. I had tried out some Bose QC 25's in JBs which were obviously pretty amazing but for a fraction of the price these things do a pretty good job. The sound is still good without the noise cancelling turned on, with the noise cancelling on sound quality goes up a fraction and it cuts out a lot of the ambient noise (air con noise, plane engine noise etc). Pretty happy with them for the price.

This is my 2nd pair, after I managed to lose my first pair in NZ. For $79 this is a good buy in the noise cancelling earphone range. I've used these on several long haul flights to the UK and the noise difference is significant. I even leave them in with no music playing because the noise cancelling is so effective and allows me to sleep! My 2nd pair stopped working after a few months & I followed the customer service instructions on the web-site & the ear phones were replaced within a week. You can pay a lot more for noise cancelling earphones, but these meet my requirements & my budget & the customer support was excellent when I needed it.

]The noise cancelling was not working form the start, there was not a single audible difference from the noise cancelling or normal set up.
Once the battery ( included form the start) was over, I’ve replaced for a new Duracell battery, and for some reason the quiet point does not turn on again
Definitely not impressed by this headphone, which in all honesty just don’t deliver what it promises.

there are more than a few issues with it, the most inconvenient are the following :
- The noise cancelling was not working form the start, there was not a single audible difference from the noise cancelling or normal set up.
- Once the battery ( included form the start) was over, I’ve replaced for a new Duracell battery, and for some reason the quiet point does not turn on again
Definitely not impressed by this headphone, which in all honesty just don’t deliver what it promises.

The sound quality from these is ok however don't expect noise-cancelling to work and certainly not the 90% (totally meaningless figure) claimed* - I should have smelled a rat! I returned the first set as the noise-cancelling was ineffective but the replacement set was no better.

* To cut a long story short, sound levels are usually quoted in dB(A) and any claimed noise reduction should be qualified by a dB figure (at specific frequency). Hence a noise cancellation should, for example, be 20db at 500Hz and not a totally subjective and meaningless like 90%.

Left my over ear NC Bose phones at home and loathed the thought of flying without them. Picked these up at Perth Airport for $99, fair price, with no high expectations? Wrong. Claimed 90‰ ambient noise reduction, not far from the truth. Pleasantly surprised by the audio quality, after adjusting the equaliser on my music player. For the price, they produce strong lows, crisp highs, and solid mid range. Noise cancelling ability defies the price, aircraft ambient noise is reduced to a whisper leaving mostly the music. On return to Perth two days later, I bought another pair. Nothing comes near these for the price, even double the price. Highly recommended.