19. The system of claim 14 wherein the MD-GMM comprises a plurality of models, each model comprising criteria associated with sounds and sources of sounds, the plurality of models comprising at least one of: a key child model comprising criteria associated with sounds from the key child; an adult model comprising criteria associated with sounds from an adult; a noise model comprising criteria associated with sounds attributable to noise; an electronic device model comprising criteria associated with sounds from an electronic device; an other child model comprising criteria associated with sounds from a child other than the key child; an age-dependent key child model comprising criteria associated with sounds from key children of a plurality of ages; and a parentese model comprising a complexity level of characteristics of sounds of adults.
19. The system of claim 14 wherein the MD-GMM comprises a plurality of models, each model comprising criteria associated with sounds and sources of sounds, the plurality of models comprising at least one of: a key child model comprising criteria associated with sounds from the key child; an adult model comprising criteria associated with sounds from an adult; a noise model comprising criteria associated with sounds attributable to noise; an electronic device model comprising criteria associated with sounds from an electronic device; an other child model comprising criteria associated with sounds from a child other than the key child; an age-dependent key child model comprising criteria associated with sounds from key children of a plurality of ages; and a parentese model comprising a complexity level of characteristics of sounds of adults. 26. The system of claim 19 wherein the audio engine is adapted to: use the parentese model to identify at least one of the plurality of segments comprising sounds having the complexity level of characteristics; and assign an adult segment ID to the identified at least one of the plurality of segments.