Onomatopoeia
The use of words (such as hiss or murmur) that imitate the sounds associated with the objects or actions they refer to.
Examples:
"Chug, chug, chug. Puff, puff, puff. Ding-dong, ding-dong. The little train rumbled over the tracks."
("Watty Piper" [Arnold Munk], The Little Engine That Could)
"Brrrrrrriiiiiiiiiiiiiiiiiiinng! An alarm clock clanged in the dark and silent room."
(Richard Wright, Native Son, 1940)
Rhyme
A rhyme is a repetition of similar sounds in two or more words, most often at the end of lines in poems and songs.
Examples
"Whose woods these are I think I know,
His house is in the village though.
He will not see me stopping here,
To watch his woods fill up with snow."
(Robert Frost, "Stopping by Woods on a Snowy Evening")
"I am not a lean mean spitting machine."
(Bart Simpson, The Simpsons)
http://grammar.about.com/od/rs/g/rhymeterm.htm
http://grammar.about.com/od/mo/g/onomaterms.htm