I found an interesting web site from an outfit that sells stuff for sensory training of cider, wine and beer judges. I find that it's useful for identifying what certain flaws smell like and what can cause them. I wondered how a judge could identify "cheese" as an aroma flaw in one of the ciders that I submitted to a competition - I guess they use these training aids to teach that..
Anyway, have a look:
https://www.aroxa.com/cider/cider-flavour-standard
Anyway, have a look:
https://www.aroxa.com/cider/cider-flavour-standard