When someone is suppressing grief, we sometimes describe the subjective sensation as "a lump in the throat." Apparently this is may be due to conflicting urges to expand or contract the muscles of the glottis.
If a person is doing this, and they try to speak, there may be some audible modulation to the sound of their voice associated with this.
Imagine you're listening to their voice on the radio only. You could call it a "shake", "quiver", or "tension" in the voice.
Is there a better, more specific word for this sound?