[inerte]

It's practically impossible to really hear the letter? It's like this short breathy growl, a hoarse autotuned cough. They all pretty much sound the same.

[mrconter11]

The volume is intentionally set quite low. You will need to turn up your volume and listen carefully to distinguish the letters.

[beardyw]

Same problem here. How about alpha, bravo, charlie etc? That's why it was invented.

[mrconter11]

Not a bad idea actually :)