This paper takes issue with the position that children's phoneme acquisition schedule is dictated primarily by auditory perceptual factors and suggests the alternative position that ease of production accounts for age of acquisition. It is felt that perceptual theory cannot adequately explain phonological development, e.g. three-year-olds produce certain sounds which they will not accurately perceive until much later and vice versa. Three psychological scaling tests are described in which adults were asked to designate certain phonemes as harder or easier to produce. These judgments were compared with the phonemes acquired by three-year-olds. A highly significant correlation between the adult ratings and children's phoneme acquisition was found. Featural analysis tended to support the hypothesis, and further confirmation was seen in the patterning of articulatory errors among children. The author stresses that these findings do not negate the importance of perceptual factors, emphasizing that he is trying to explain not the dynamics of phoneme acquisition but rather the schedule which it follows. It is, however, emphasized that there is no compelling evidence for perceptual theory, and certain observations which either militate against perceptual theory or encourage alternative speculation are discussed. (FWB)