Well, PCM is just a chunk of headers followed by a load of samples. Try finding an audio editor that lets you open files as raw sample data, and set the sample rate manually as you open it, and then you can save it back as wave. I *think* GoldWave let you do that:
http://www.goldwave.com/
But don't quote me on it, it's been years since I've last used it.
Jonathan
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for(74,117,115,116){$::a.=chr};(($_.='qwertyui')&&
(tr/yuiqwert/her anot/))for($::b);for($::c){$_.=$^X;
/(p.{2}l)/;$_=$1}$::b=~/(..)$/;print("$::a$::b $::c hack$1.");