And also Stuart, try not to tighten that sphincter when pressing on brake 

:-)

Ab

On Mar 16, 2018, at 12:21 PM, David Beierl <dbeierl@attglobal.net> wrote:

>>  Nothing explains the frequency change with pressure. I can play a tune while coming to a stop, and then it stops.  
> 
> Believe it or not you may be perceiving the tone differently because of your foot pressure.  I can notice the effect when I clench my teeth while listening to a tone.  Get someone else to press the brake while you listen.
> 
> Yrs,
> d