Educating yourself HOW to hear this stuff takes time. Plus - if you're doing it in your bedroom and a set of average speakers - you may not perceive any difference at all.... HOWEVER, that doesn't mean it won't affect your mix.
What's your listening environment? What room? What speakers?
Listen to the transient sounds (and ss sounds - they'll distort). Listen to the difference in the word "truncheon".
first - set the threshold pretty low - so it's compressing most of the time. And set the ratio high - 8:1 or more.... this way you'll be able to hear what the compressor is doing....
Fast Attack / fast release - it'll sound like tRUNCHEON.
Fast Attack / slow release - it''l sound like truncheon
Slow Attack / fast release - it'll sound like TRUNCHEON
Slow Attack / Slow Release - it'll sound like TRuncheon
Once you've established what it's doing then you can back off until you have what you need. A good way to set up a compressor IS to start with fast attack, fast release, low threshold and high ratio - to really hear what's going on (and probably what you don't want). For me - I then get the attack slower until the right amount of the "front" of the sound is coming through. Then I back off the release until it bounces the way I want. Finally I reduce the ratio and back off the threshold until it works the way it's supposed too.....
I agree, let's say I was recording a song about poultry.
Slow attack / slow release - COC...oh
'You know it's a bad role when Nic Cage passes on it.'