Consonant Name Question

สวัสดี

I have a question about the consonant names. I know that they're named for the sound + word that starts with the letter. But what about consonants like 'ฆ'? It's word is ระฆัง, which starts with 'ร', not 'ฆ'. others include 'ฑ', 'ษ', 'ฬ', 'ฮ', and 'ภ'.

I hope I'm not just being silly. Thanks in advance!