No it isn't. Siren Head is an urban legend made by Trevor Henderson, mainly known for his odd appearance.

Was siren head a human?

Siren Head was never a person; people cannot be turned into an example of it. Weapons do not normally work on the entity. It has almost never been spotted in populated areas.

Is there such thing as a siren head?

A creation of artist Trevor Henderson, Siren Head is a tall fleshy creature whose head is a pole with two speakers attached. It lurks in wooded areas emitting disturbing noises. Sometimes they are distorted radio reports, or weird garbled pieces of music. Sometimes it's distressed people screaming for help.