Multifunctional actin-bundling protein. Plays a major role in regulating the organization, dimensions, dynamics and signaling capacities of the actin filament-rich, microvillus-type specializations that mediate sensory transduction in variouS mechanosensory and chemosensory cells. Defects in ESPN are the cause of deafness autosomal recessive type 36 with or without vestibular involvement (DFNB36). A form of non-syndromic sensorineural hearing loss. Sensorineural deafness results from damage to the neural receptors of the inner ear, the nerve pathways to the brain, or the area of the brain that receives sound information. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.