Change in pitch of voice... I am not sure. Does anyone else notice it?
Hiccups are due to irritation of the diaphragm (which is a layer of muscle separating your chest from your belly). When it is irritated it goes into a spasm, which forces air out of the chest. This produces a hiccup. Some of the reasons why people have irritated diaphragms... 1. changes in food intake (more/less/different kinds/different times, etc), 2. heartburn and reflux, 3. Nervousness and air-swallowing, 4. we don't know. It's actually more common that we don't know. But these things don't usually last and they will go away.