My experience of hearing tests is varied. During some of them you can hear the background noise change when it transmits, which makes it ridiculously easy. On others, if you are sat in the supposedly soundproof box as someone is flying overhead, you'd struggle to hear recordings of a bull elephant's mating call through the headphones.
What I'm trying to get at is (and I'm not suggesting the AFCO has a rickety old hearing test although it is possible) along the lines of what Mick Strigg said. Give it a go and you may perform differently on the day.
BV
Oh, and well done for writing an eloquent and grammatically correct post. According to the grammar police on this site you're halfway to being an Officer already!