After Sinus Surgery, Will the Nasal Quality of my Voice Go Way? I Had a FESS, Clean out and Turbinate Reduction 8 Weeks Ago.

If anything the voice normalizes after sinus surgery because the nasal congestion improves so speech not hyponasal.  Many patients after sinus surgery notice a voice change because the normal resonance provided by the nose and sinuses has been restored so it sounds different to them.  However those listening to you hear the same voice.  If your voice really is more nasal then may have excessive swelling although it should have subsided by now.  Consider allergy especially if there are other allergic symptoms which could cause nasal congestion and hyponasal speech.