In designing telephone system, we sometimes deliberately introduce a little noise, otherwise the end user might think the connection has been lost:

http://en.wikipedia.org/wiki/Comfort_noise

That’s what wearing the Sony (well, that particular model) reminds me of.

A few weeks later (and back in Australia) I wanted to buy a NCH for myself. Since I didn’t record either the brand or the model, I wasn’t able to buy the pair I tried. Instead I bought a Sony MDR-NC20 ex USA, which looks similar in format to the Sennheiser PXC350 you mentioned, for about US$250. I figured good brand plus paying enough must equal decent performance.

I’m still kicking myself. While the Sony I got cancels noise, and is reasonable to play music, its performance in both areas was and is just plain ordinary. No WOW factor whatsoever on either front.

I clearly remember being shocked by the pair I tried. Did I mention the bit about kicking myself?

The above article has an interesting review of the Bose QC 15. It seems that some people experience some discomfort from the active noise cancellation and Bose has a 30 day return policy for them.

Aigars: Thanks for the suggestion, one thing to note is that I am not looking for audiophile information. In terms of music quality I was happy with using RF to play music from my iRiver in my car. My main aim here is not good music quality but an absence of annoying noise.

Toby: 20dB of noise reduction sounds good, but E250!!!

Obey: Thanks for the suggestion, but I find that forums tend not to be very useful to outsiders. Also I have received other suggestions of in-ear monitors. Some people report great success, but such things annoy me and I can’t use them. I would much rather have hot ears!

E S Lim: The Audio-Technica.com site is designed for Flash, and when you don’t have Flash it demands the use of cookies before showing me any information on their products. Such a poor web site makes me hesitant to buy any technology products from them.