Thirty-one university students rated and transcribed sentences spoken by a native English talker and a native Dutch talker speaking English.  The students were seated in a classroom, and the sentences were presented in four randomized conditions:  from a conventional classroom loudspeaker placed in front of or above the students, and from a loudspeaker optimized for speech reproduction - also placed in front of or above them.  At the front of the classroom was a muted video recording of one of the talkers delivering an online lecture. Results showed front-located loudspeakers yielded less cognitive effort, better sound quality ratings, and better word clarity - showing the importance of congruence of loudspeaker/talker position. 

This work was published in 2024 in the journal Building Acoustics:  DOI: 10.1177/1351010X231217139