Vowel sounds are low pitched voicePractice lower-pitched voice, practice deep, diaphragmatic breathing for better breath support and resonance, keep good posture, relax your jaw and tongue, and gently lower the larynx by relaxing your throat muscles, as if you are humming, yawning or snoring. Vowel sounds can help to relax the vocal cords - not much sound from vocal cord allowing for a deeper, more resonant sound from pharyngeal and sinuses.