When we talk, especially in english, our voice has high and low moments, a lot like music. people are sometimes trained in pitch using music. There are a few patterns like:
this is a table. the "ta" in table gets a slightly higher pitch.
How are you? if it's been a long time, sometimes we emphasise the "are" with stress and a rise in pitch.
I just happen to write a paper about it the other day.
- For Teachers