George and John,

they are very simple to build and with sounds available online at no cost they very economical.

you need the following:

speakers that come with 3.5 mm cable, 1 or 2
http://www.walmart.com/ip/12029442?...552&wl4=&wl5=pla&wl6=61410434104&veh=sem

mini amplifier
https://www.radioshack.com/products/radioshack-mini-audio-amplifier?variant=5717614213

3.5mm cable male to male to hook amplifier to your phone, many lenghts available.
http://www.amazon.com/Mediabridge-3-5mm-Stereo-Audio-Cable/dp/B004LTEUDO

3.5mm splitter
ONLY needed if you use 2 speakers
http://www.amazon.com/Belkin-Speake...50470263&sr=1-1&keywords=3.5+mm+splitter

cable ties to tidy up the cords

all fits inside...