Contralateral Routing of Signal Systems Can Improve Speech Recognition and Comprehension in Dynamic Classrooms

Objective: The purpose of this study was to evaluate the effects of hearing aid-based rerouting systems (remote microphone [RM] and contralateral routing of signals [CROS]) on speech recognition and comprehension for children with limited usable hearing unilaterally. A secondary purpose was to evaluate students' perceptions of CROS benefits in classrooms. Method: Twenty children aged 10-16 years with limited useable hearing in one ear completed tasks of sentence recognition and comprehension in a laboratory. For both tasks, speech was presented from one of four loudspeakers in an interleaved fashion. Speech loudspeakers were either midline, monaural direct, or monaural indirect, and noise loudspeakers surrounded the participant. Throughout testing, the RM was always near the midline loudspeaker. Six established users of CROS systems completed a newly developed questionnaire that queried experiences in diverse listening situations. Results: There were no effects of RM or CROS use on performance for speech presented from front or monaural direct loudspeakers. However, for monaural indirect loudspeakers, CROS improved sentence recognition and RM impaired recognition. In the comprehension task, CROS improved comprehension by 11 rationalized arcsine units, but RM did not affect comprehension. Questionnaire results demonstrated that students report CROS benefits for talkers in the front and from the side, but not for situations requiring localization. Conclusions: The results support CROS benefits without CROS disadvantages in a laboratory environment that reflects a dynamic classroom. Thus, CROS systems have the potential to improve hearing in contemporary classrooms for students, especially if there is only a single microphone.