Touch the tip of your tongue to the roof of your mouth just behind your teeth. Add vocal cord vibration as you release.

Americans pronounce dumb as DUHM (/dʌm/). It's 3 sounds in 1 syllable. Short, clean, and front-of-mouth — every sound earns its place.
Record yourself saying "dumb" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 3 sounds. Explore each sound's mouth shape and how it's made.
Touch the tip of your tongue to the roof of your mouth just behind your teeth. Add vocal cord vibration as you release.

Relax your lips, jaw, and tongue completely. Drop your jaw slightly and keep the tongue neutral.
Press your lips together. Air flows through your nose. Vocal cords vibrate.
