Need a battery for your Arduino that is high enough to regulate the voltage to down to a solid 5V? Well here comes the 9V Snap to 2.1mm Barrel Plug Cable to your rescue! It allows you to plug in 9V and 7.2V rechargeable batteries to anything with a 2.1mm Barrel jack on it.
Convert your sound files to .AD4 and store them on an microSD card for instant audio playback. Either use a simple button control or two wire serial communication from a microcontroller to activate the sound files & play them through a speaker. This audio player is super small too!