Have them record raw data on how the person speaks and how the person manages a conversation. If there are any incidental notes, include them separately from the data.
[header] How to help an autistic person develop voice prosody [title] Start with an assessment. [substeps] In this case, the assessment questions being a) how does the person speak now, and b) how does this impact communication and conversation? Select a team of highly observant people. These may include friends of the person, teachers, parents, support people and others.