ABSTRACT
The ability to produce, perceive, and comprehend speech is a remarkable human achievement. In the most simplistic terms, spoken language is concerned with transferring ideas from one person’s head to another person’s head with the common physical link being the vibration of molecules in the air. It involves the transformation of thoughts into sentences and words and, ultimately, a series of articulatory commands sent to the vocal apparatus. These sound waves then produce mechanical changes on the cochlea (part of the inner ear) of the listener. These are perceived as speech and the words, sentences and meaning are inferred from this input. Speech recognition and speech production are often studied separately from each other, and it can be helpful to think about them as separate tasks. However, it is important to recognize that the driving force behind human language is to communicate ideas to the people around us. Outside of the laboratory, speech production normally only exists when someone else is around to engage in the complementary process of speech recognition. This social aspect of language implies that we are able to deduce what other people know, what they believe and what they do not know. It is highly questionable whether the vocalizations of other animals could be said to be “true language” in this sense.
