[rbarrell]

Bought a new pair of the sony noise cancelling headphones and all is well and dandy except for the horrible thudding noise in my ear when I walk. This only happens when the NC is switched on and if my foot lands too heavily I also get a crackling noise in my left ear. Are they faulty or is this normal?

 

[Hyoobris]

Try replacing the battery. The crackling is usually the result of low battery.

 

[VulgarDisplay]

Cable microphonics?  Hold on the the cable and don't let it hit your body then jump up and down.  See if the noise persists.  

 

[SHURE530]

I know it's an old post.
But whatever, I'll give my 2cents.

It's normal.

Try it with with other headphones, there will be a soft thud every time your feet touches the ground.

Hence I only wear headphones while I'm in-active.
Earphones for walks and gym