Every living creature––in virtue of being alive––exhibits an impulse to express itself, whether that creature is an ant or a mastodon. Only humans, however, use language (in the fullest sense of this semiotic system’s hypostasis) to express themselves, and this applies fully even to those persons who are cognitively or physically impaired, and whose speech suffers in the bargain.

This latter condition was brought home to Y-H-B when I visited the local gym and had my tri-weekly fitness session with my trainer. Two others––one a young man, the other an older fellow––who were there were both cognitively impaired. Both are guided through their exercises by my trainer. One of them in particular (as the result of a serious injury) exhibited all the symptoms of echolalia, which is described (in its Wikipedia entry) as follows:

Echolalia (also known as echologia or echophrasia) is defined as the unsolicited repetition of vocalizations made by another person (by the same person is called palilalia). In its profound form it is automatic and effortless. It is one of the echophenomena, closely related to echopraxia, the automatic repetition of movements made by another person; both are “subsets of imitative behavior” whereby sounds or actions are imitated “without explicit awareness”. Echolalia may be an immediate reaction to a stimulus or may be delayed.”
The word “echolalia” is derived from the Greek ἠχώ, meaning “echo” or “to repeat”, and λαλιά (laliá) meaning “speech” or “talk” (of onomatopoeic origin, from the verb λαλέω (laléo), meaning “to talk”).”

To hear echolalic speech is to realize how precious the human capacity for language is, and how tragic when it is seriously impaired.