1. A method comprising: capturing an audio recording from a language environment of a key child, segmenting the audio recording into a plurality of segments; identifying a segment ID for each of the plurality of segments, the segment ID identifying a source for audio in the segment; identifying a plurality of key child segments from the plurality of segments, each of the plurality of key child segments having the key child as the segment ID; estimating key child segment characteristics based in part on at least one of the plurality of key child segments, wherein the key child segment characteristics are estimated independent of content of the plurality of key child segments; determining at least one metric associated with the language environment using the key child segment characteristics; and outputting the at least one metric.