My voice got more resonant and deeper

[๕ඞChick3ncu1ry]

Things I have changed

-abdominal crutches
-bridge pose
-plank
-diaphragmatic breathing exercise before bed
-squat, lunges, calf raises, leg presses all weighted
-chest press, push up, lats pull down
-neck curl

-more protein rich diet, more salt, less sugar/carbs

 

[noodlelover]

Testosterone makes a big difference.

You can train a deeper more resonant voice directly as well. The vocal cords, airway, and throat are all composed of muscles that are controllable with practice.