Yes! On one of VoiceThread’s Comment assignments, any new comment a student posts, even if it’s in response to another student’s comment, will count towards the number of comments you’ve required them to add for the assignment. The student will even see on the right column of VoiceThread’s Assignment platform an indication (i.e., a checkmark) that they have left a comment and it has been counted towards the assignment’s requirements.
If you’re assessing students with a VoiceThread Comment assignment, it’d be a good idea to share with them this VoiceThread student guide: Submitting New Assignments.
Also, you can learn more about setting up a Comment assignment in VoiceThread’s How to Use New Assignments guide.