Electronic Mute for Trumpet & Cornet

This is a mute system for the trumpet and cornet.
Can be used as

1- a passive mute (seal all the holes at the bottom to the outside apart from the pipe output).
2- Electronic mute, place a condenser microphone at top, put a small amplifier circuit inside and a voltage boost circuit for converting 1.5V dc to the required voltage for the amplifier.

here is my voltage converter
http://www.ebay.com/itm/DC-DC-Boost-Converter-Step-Up-Module-1-5V-to-5V-500mA-for-phone-MP4-MP3-Arduino-/351390823155?pt=LH_DefaultDomain_0&hash=item51d08672f3
I've ordered these but not tested yet for the microphone amplification
http://www.ebay.com/itm/1pcs-Microphone-MIC-amplifier-module-Voice-Module-NEW-/201226168458?pt=LH_DefaultDomain_0&hash=item2eda03a88a

(UPDATE, tried these modules and they seem to work with a small speaker. should be all ok for headphones. )

I've made a prototype with the circuit schematic above. It works, but could be better.

For obtaining a proper reducement in the sound passing thru the mute, all holes must be sealed from inside with something like a glue etc. Only the pipe output should stay open.

If you have recommendations about the project, circuit schematics etc., post comments please.