- Phase 2: After completing the assessment session, phase two will include 1 to 3 separate parts examining 3 different TTS features (e.g., speech presentation rate, text highlighting, speech production quality). Participants can choose to participate in 1 or more parts within this phase. For each part, participants will first listen to or view selected variations of a target feature and choose their preferred variation. For each study, participants will then complete five or four experimental sessions lasting up to 90 minutes each. Parts with up to five sessions (i.e., Part 1 and 2) will include features with more variations than those included in Part 3, which will include up to four sessions. Participants will read and/or listen to up to 12 reading passages in each session and answer multiple choice comprehension questions related to the content of the passage. At the conclusion of each session, participants will provide their opinion about the optimal targeted feature variation using rating forms and interview questions. Participants will read and/or listen to the passages via a computer.