title: Acoustic analysis of the acquisition of acceptable r in American English.
mesh_terms: D000162:Acoustics; D000328:Adult; D000367:Age Factors; D001307:Auditory Perception; D002675:Child, Preschool; D004193:Discrimination Learning; D006801:Humans; D007100:Imitative Behavior; D007804:Language Development; D009034:Mother-Child Relations; D013016:Sound; D013060:Speech; D013064:Speech Disorders; D013637:Tape Recording; D014705:Verbal Behavior