To elaborate, at approximately six months of age (Lenneberg, 1967) the child's initial cooing sounds change into babblings that resemble one-syllable utterances. Each of these utterances (e.g., "ma", "da", "di", or "mu") is represented as a whole tonal pattern, rather than as individually produced consonant or vowel units. Because of the limited articulatory control of children at this stage, only a small number of discernible utterances are expressed, and there is a universal similarity among these sounds. That is, they are not language or culture specific.

Out of this group of random utterances, certain sounds begin to acquire meaning for the child. These sounds are made meaningful by adults (uiz., parents); the child initially simply produces the utterances. The words "mama" and "dada" illustrate this developmental sequence. In accord with the maturational level of the vocal apparatus, the child is capable of uttering such sounds as "ma" and "da". When these sounds are produced (being done in an unpurposeful manner), he perceives a noticeable change in his environment. His parents respond in a specific manner to these sounds, and react to them differently than to other sounds. Considered behavioristically, through the process of association (and subsequently, reinforcement) the child attaches meaning to the "ma" and "da" utterances only because his parents do so.

It is of note that many different languages use similar sounds to indicate father, for example: Spanish-papa'; Russian-papa; German-Papa; Swahili-baba; Turkish-baba; Hungarian-apa; Croatian-tata (Langacker, 1967). This additionally suggests that certain single-syllable random utterances acquire meaning for the child merely because his parents choose to recognize them as meaningful. The child does not "consciously" produce (indeed, he has no concept of) individual phonemes, and then integrate them into words during the initial stages of language acquisition. He does not segment words and identify phonetic elements; rather, he acquires word patterns and structures (Lenneberg, 1967).

Up until the point when the phonemes begin to be recognizable, there is no explicit evidence that the language the child has heard has any effect upon him. However, once the utterances of children in different linguistic cultures can be distinguished, clearly the language heard has had some effect. That is, the child's listening processes have begun to affect his utterances.