1
Write one representative passage
Use roughly the kind of text you will publish: a natural opening, a longer sentence, names or technical terms, and punctuation that should shape the pauses. Keep a copy of the exact wording so each candidate receives the same test. If you have several use cases, prepare a separate passage for each instead of combining incompatible goals.
2
Record the conditions
Note the voice selected, available settings you changed, and any edits to the script. Match speaking style as closely as the interfaces allow, but do not pretend unlike controls are equivalent. If a required option is unavailable or unclear, record that as a workflow finding rather than silently changing the test.
3
Listen blind, then inspect the workflow
Give the files neutral names and listen without watching either interface. Score intelligibility, pronunciation, pacing, and listener fatigue; have another person review them if the stakes warrant it. Afterward, check the practical requirements that audio alone cannot establish, such as permitted use, output handling, and how revisions would fit your process.