In COT-CAUGHT unmerged American dialects, you hear COUGH with a less rounded /?/ The latter vowel is not not completely rounded. You need to add that IPA subscript "less rounded".
Blonde is with /a/ .
You can study about LOT-CLOTH split. It usually occurs before /f/, /s/, /th/, /g/ and /ng/
Thanks raindoctor. What are LOT-CLOTH split & COT-CAUGHT? How can I get the information? Could you please introduce a source to brush up my information?