Sometimes you experience such intense joy that you cry a little as you talk. Other times you have such a bad day that you feel a certain heaviness when you speak. The overwhelmed voice doesn’t discriminate. It comes with joy. It comes with sadness. When it strikes, your emotional stamina buckles under its weight.
The overwhelmed voice can be used to show intense emotion that is difficult to manage. The kind of emotion that affects a character's ability to think. It is the emotional overload that causes them to act unexpectedly and is typically associated with intense sadness. Once in a while, though, it can also be used to portray happiness, especially when sudden and unexpected.
Think of great sadness in a story, especially in moments right after a break-up or death of a beloved character—the parts where a character has to exhibit strong emotion that the audience can relate with. The overwhelmed voice is often used in sad movies, emotional scenes, and sometimes in comedies to show extreme happiness.
An overwhelmed voice is entirely dependent on the emotion a character wishes to express. It can be the quiet, gloomy, and depressing tone used when one is about to cry. It can also be emotional and passionate, when used to show an unexpected good gesture.
The overwhelmed voice is difficult to express. The emotion has to be captured just right, or you risk devaluing a moment or making it seem inauthentic if the emotion is over-expressed.