Describes the moment where a male's voice cracks, especially with strain such as with shouting. The voice pitch suddenly rises and the contrast with the normal deep voice makes it sound like a squeak or 'pop'.
Especially used to describe teenage boys who are undergoing voice deepening during puberty; where vocal cords lengthen and thicken in response to testosterone from the testes. (Hence the use of the word 'teste' and 'pop'.) However, this term can be used to refer to young adult men as well.
"Jay just had a massive teste pop during his choir solo practice!"