Acts as a transcriptional activator. Acts by binding to sequences related to the consensus octamer motif 5'-ATGCAAAT-3' in the regulatory regions of its target genes. Involved in the auditory system development, required for terminal differentiation of hair cells in the inner ear. Interacts with ISL1. Preferentially localized in the nucleus. Expressed in the chochlea of the inner ear. At E14, strongly expressed in cochlear and vestibular hair cells of the inner ear, in the cochlea at E18 and coninues to the adulthood. Belongs to the POU transcription factor family.