Phonetics is the branch of linguistics devoted to the study of the events associated with the production of human speech sounds. Phonetics is concerned with the human noises by which the thought is actualized or given audible shape: the nature of these noises, their combinations, and their functions in relation to the meaning. By extension, it is also the study of the perception of these sounds, and of their physics. Phonetics is therefore anchored in anatomy, psychology, and neurology. Phonetics, however, is basically not concerned with meaning, in that respect it differs from all other branches of linguistics.