Final answer:
The question refers to the earliest stages of language development and speech perception in children, particularly focusing on the period when they can discriminate phonemes and start producing single-word utterances.
Step-by-step explanation:
The student is asking about the earliest level of detection of a 'sponsee' word, although the term 'sponsee' isn't standard. However, interpreting the question to relate to the earliest stages of language acquisition and speech perception, it could be considered under the study of linguistics, which is an aspect of the broader field of Biology in relation to human development. Particularly, the focus is on the period when a child first begins to recognize and produce words.
At the earliest level of language detection in children, they are able to discern phonemes, which are the smallest units of sound in speech. A child between the ages of 1 year to 18 months is typically at the stage where they produce single-word utterances, and these words can carry a larger meaning, extending beyond mere identification. The child's ability to discern phonemes from all human languages narrows down to only those phonemes used in the languages they are exposed to by the time they are about 1 year old.