When we speak, we tend to speak in ‘chunks’ – small groups of words. Each chunk has its own change in intonation and there is usually a brief pause before the next chunk. We call these chunks ‘tone units’ and these units appears to be one of the basic building blocks of speech. A tone unit is the minimum unit of speech which can carry intonation. It is typically a few words in length but can be a single word or syllable. Other terms for this unit are ‘intonational unit’ or ‘foot group’.
Difference Between Pitch and Tone
The difference between pitch and tone is very small and not easy to understand. Don’t worry if you still don’t understand after reading this – it will take some time before you do. Pitch is proportional to the fundamental frequency (F0) of a sound. However, pitch refers to how the human mind perceives (hears) the sound whereas frequency is an objective measurement that we can make with an instrument. The human auditory system is actually very sensitive to changes in pitch and pitch is one of the prime factors in creating perceived stress.