1. The study and systematic classification of the sounds made in spoken utterance as they are produced by the organs of speech and as they register on the ear and on instruments.
2. The practical application of this science to the understanding and speaking of languages.
3. The system of speech sounds of a language or group of languages; for example, “He reads Portuguese with some ease but finds its phonetics difficult.”
4. A written representation other than conventional spelling; such as, “The use of thru is considered a fair phonetics.”
5. The science of speech and of pronunciation; phonolgy.
6. The analysis and description of speech sounds in terms of the processes by which they are produced (articulatory phonetics), the physical properties of the sounds themselves (acoustic phonetics), and the relation of these properties to the articulatory and auditory processes.