Mutual Intelligibility

When two persons communicate through spoken language, thoughts that enter into the mind of the speaker first have to be expressed in terms of the vocabulary and grammatical structures of the speaker's language. The mental linguistic structures are then used to make the speaker's vocal organs move so that they produce audible sound. The sounds travel through the air (or some other medium – e.g., a telecommunication channel) and then impinge on the ear of the listener. The result is that the listener hears a stream of sounds. If the listener is familiar with the language, he or she will recognize (the same) linguistic units (e.g., words) in the same order in which they left the speaker's mouth. This part of the communication process is what we call speech recognition. If a sufficient number of units have been correctly recognized in the correct sequential order, the listener will be able to reconstruct the original thoughts and intentions of the speaker. This last part of the process is what we call speech understanding or comprehension. The sequence of events sketched here is known as the speech chain (Denes and Pinson 1963), and it has been the blueprint of Levelt's (1989) model of speech production and Cutler's (2012) model of native listening.