Custom hearing protection for Musicians

[jazzyvee]

I had some custom IEM/ACS earplugs made from a mould taken of my ears at the Custom IEM stand on the London Bass Show this year.  They arrived a few weeks back and I've tried them on two gigs so far and in the main they seem to be fairly flat in terms of their frequency response and have 17db attenuation. However I have identified an issue which to be fair both IEM and ACS ( manufacturers) are going to look into for me.  
 
Firstly when I move my mouth on stage i.e. laughing or smiling with the band members or punters, there is leakage of sound round the sides of the insert. This apparently can be fixed by making them a bit better fitting.
 
The second point is of more concern I think and I wonder if anyone here has had the same issue.  
 
When slapping and popping the popped note sounds about a semitone flat which I found very confusing. Fortunately I was playing a fixed part so I could ignore it as I could see I was hitting the correct notes.
 
But I could see if being a problem if I was doing an improvised solo or not watching my fingers. Has anyone else noticed that.  
 
Jazzyvee

[dannobasso]

I have 2 sets of custom Westones and have the solid plugs for maximum protection. My first set was very good but would back out a bit due to onstage antics. I had another set made a few months back and they are excellent. It is a very deep impression and the 5 way monitors that use the same mold have no leakage what so ever.  
 
I have never experienced a tone differentiation at all,
http://www.westoneaudio.com/index.php/products/hearing-protection/es49-custom-hearing-protection.html

[keith_h]

The leakage definitely sounds like a fitting problem. It might be the ear molds themselves or the manufacturing process. A dumb question but did you put the ear plugs in the wrong ears? I've made that mistake before.  
 
When wearing my earplugs I don't notice any intonation problems. I do notice sounds that are  present when I do not wear the plugs are subdued or missing when I do wear the plugs. Slap and pop sound duller. I attribute this to the hearing loss I have built up over the years being accentuated by the earplugs. As a lot of the pop and slap sounds are fret and string noise related these could be up in a frequency range where you already have some loss and their disappearance sounds like loss of intonation. A hearing test would show where you have loss and see if this is a feasible explanation. The most common range is between 3K-6K but others are possible depending upon your noise history.  
 
Keith