When the gas flow line is blocked in the oral cavity, it is not completely closed and one side of the tongue between the top or sides of the mouth, the sound produced will be classified as sidetone.
When air flow is blocked in the middle line of the mouth and the closure between one or both sides of the tongue is incomplete, the resulting sound is classified as a side tone.
When the air flow is blocked in the middle line of the mouth, and the closure between one or both sides of the tongue and the top of the mouth is incomplete, the sound produced will be classified as side sound.<br>