The "fifty sounds" are not really fifty in number. There are only about forty-six of them, and in modern times they are arranged as follows, in an order called "gojuuonzu" ("fifty-sound table"):
a i u e o
ka ki ku ke ko
sa shi su se so
ta chi tsu te to
na ni nu ne no
ha hi fu he ho
ma mi mu me mo
ya yu yo
ra ri ru re ro
wa wo
n
The above table is to be read by rows. It starts a, i, u, e, o, ka, ki,...
This is NOT a complete list of sounds in the Japanese language!