I think genetics have some role in this as well, so look at the guys in your family to see how theirs look.
This is what wikipedia has to say:
The laryngeal prominence is usually more prominent in adult men than in women or prepubescent children. The growth of the larynx itself during puberty is responsible for the vocal instability in teenage boys. The laryngeal prominence is merely the protrusion one sees of the thyroid cartilage making up the body of the larynx. The laryngeal prominence is usually more prominent in adult males because the thyroid cartilage elongates during puberty, protruding out the front of the neck more noticeably. The result is that the two laminae (thin cartilage) of the thyroid cartilage that form the protrusion meet at an average angle of 90° in males, and 120° in females, so there is less cartilage protruding out in females.
So basically, it appears when puberty kicks in and when the inner-neck changes. Seeing that FtMs get voice drops due to changes in the larynx (from my understanding

), it could be
possible that the thyroid cartilage/adam's apple could become more prominent as well. I can't confirm anything about this though since I'm not on T and I have no idea what my levels are. I really think the only reason I have a prominent one is through genetics, though I'm starting to wonder if I could possibly be intersexed in some way

. Any way a female bodied (unknown chromosomes), with periods, and normal feminine stuff besides fat retention could be interesexed?