Literally it would be Esion s`nekcihc elttil, but the real answer you are looking for is PEEP.
You see a palindrome is something that reads exactly the same forwards as backwards as in this example said to be a quotation of Naploean when he was exiled from France to the island of Elba (though why he would say anything in English is illogical so I think this is highly apocryphal):
Able was I ere I saw Elba <-- Notice that if you look at it from this end, it reads the same.
So the word PEEP is a palindrome of itself as is the word LEVEL
PEEP
peep
peep
peep
peep
peep
peep
gbgfg
peep
A palindrome is a word, phrase, or sequence of characters that reads the same forwards and backwards. An example of a palindrome is the word "radar". A chick's noise could be described as a "cluck" or a "peep".
toot
pop
A palindrome that is a synonym of "sudden noise" is "pop," as it reads the same forwards and backwards.
peep
toot
toot
toot
tot
pup
Peep