When I travel by train, which I do about one and a half times a week, I listen to music via headphones. This is partially to mask the sounds of the train itself and partially to mask the sounds of other passengers - Israelis are not the type to sit quietly! I have noted that I really have to crank the volume up, to listen at a much higher volume than I would prefer.
As a result, I have started to suffer from tinnitus, which manifests itself as a wash of white noise at a high frequency. Fortunately, it comes and goes; it's barely present on the days when I don't travel. I would like to reduce the volume in my headphones when travelling, which is what leads me to noise cancelling headphones. These should allow me to listen at a much lower volume whilst shutting out all the extraneous noise.
Being slightly old-fashioned (these days, this means a year or two behind the times), I prefer to store my music on a TF card as opposed to storing the music on my telephone and transmitting to the headphones via Bluetooth. After searching on Ebay for noise cancelling headphones which can accept a TF card, I ordered one such device for the princely cost of about $25. The headphones arrived very quickly, but before I could use them, I had to photocopy and enlarge by 50% the very small user instructions. Thus armed, I could understand what I needed to do in order to play music stored on the memory card.
The initial volume was extremely loud; after pressing on the correct button to reduce the volume, I tested the noise cancelling functionality ... which did not seem to be present. I got in contact with the suppliers, who very quickly responded that another purchaser had asked the same question recently. It turns out that there is no noise cancelling, which is why some of their advertising material does not mention this (but their headline does). In other words, these headphones are functionally the same as the ones I already use. The new headphones have bluetooth and make announcements, but the controls are harder to access and I couldn't see how to fold them (the picture on the left is not of the model which I purchased).
In other words, I was duped. I will keep these headphones in reserve for the day when my main headphones cease working, but otherwise I'm back where I started. Looking again at Ebay listings, it would seem that any decent pair of noise cancelling headphones is going to cost over $100 and will be made by a respectable manufacturer, eg Bose or Sennheiser. None of the models which I have found accept TF cards (I wonder why), but all have either Bluetooth or the ability to connect to an external mp3 player. I shall continue looking ....