In depends in what context you are using the onomatopoeia, do what seems right. When using it as a hook at the beginning of an essay or short story, I would. ex. "Bang!" Alex's body lay motionless in the soil. Usually you would, but in some instances it is not nessecary. ex. The book fell off the shelf, boom! Quotations could still be used here, but are not required.
A wail
wale and whale
The definition of the word lament is to wail loudly.
A wail is a prolonged cry of despair, or the sound made by emergency vehicle sirens.
The Igbo meaning for the word wail is "Kwa arịrị."
Wail al-Shehri died on 2001-09-11.
Wail al-Shehri was born on 1973-07-31.
wail........... i think
Some of us can hear the whale wail. Others feel it from afar.
Vetting Wail - 2009 was released on: USA: May 2009
sirenwind
Yelled is not an onomatopoeia:)