PROJECT ABSTRACT Inner ear dysfunction and the associated problems with hearing and balance affect about 30 million Americans and that number is expected to grow as the population ages. Despite the enormous socioeconomic impact, however, hearing and balance are the most poorly understood of all the senses. One significant reason for this gap in our knowledge is the technical difficulties unique to inner ear research that are a discouraging barrier to new investigators. To address this challenge, we have designed an ambitious three-week course, the Biology of the Inner Ear (BIE) course, to train new investigators in advanced research approaches to the biology of hearing and balance. In each course, 18 students are taught by a team of leading scientists and clinicians. The course will be held in the summers of 2021, 2023 and 2025 at the Marine Biological Laboratory (MBL) in Woods Hole, MA. For the intervening summers of 2022 and 2024, we plan on-site orientation programs for faculty from under-represented groups or who are hearing impaired, with the goals of increasing the diversity of faculty role models at the BIE course and attracting a greater diversity of students. The BIE course was first offered in 2007 and thereafter biennially through 2019. Each course was very well-received by students and faculty, and their feedback provided successive improvements, culminating in the present curriculum. Using the focused approach that typifies other highly successful MBL courses, BIE is designed to meet specific needs of new researchers in auditory and vestibular science. The course will continue to enroll a class comprising graduate students, postdoctoral researchers, clinician-scientists, and established investigators entering the field for the first time. These talented students will be provided with instruction and hands-on laboratory training in cutting-edge, rigorous techniques and specialized methods that are unique to investigations of the inner ear and auditory, vestibular, and lateral line systems. Through lectures, research seminars, roundtable discussions, tutorials, and informal interactions as students and instructors work side-by- side in the laboratory, the BIE course will foster the development of the students as investigators and provide the opportunity to establish long-lasting mentoring relationships. These interactions will emphasize problems, concepts, and theories that are driving current research; innovative approaches; and strategies to translate discoveries into meaningful improvements in human health. BIE is designed to enhance the pipeline of talented, highly motivated scientists entering the field, providing instruction that will challenge them and help them undertake independent and original research, and introducing them to networks within the hearing and balance community that will encourage their career development. This training will advance the pace of scientific discoveries and promote their translation into treatment...