subvocalizer vs subvocaliser

subvocalizer and subvocaliser both are nouns.

Word	Noun	Adjective	Verb	Adverb
subvocalizer	Yes	No	No	No
subvocaliser	Yes	No	No	No

As nouns, subvocalizer and subvocaliser are synonyms defined as:

subvocalizer and subvocaliser: someone who articulates speech without uttering sounds

subvocalizer (noun)	subvocaliser (noun)
someone who articulates speech without uttering sounds	someone who articulates speech without uttering sounds