Hearing is essential for the courtship of one of the major carriers of human disease, the mosquito. Males locate females through flight-tone recognition and both sexes engage in mid-air acoustic communications, which can take place within swarms containing thousands of individuals. Despite the importance of hearing for mosquitoes, its mechanisms are still largely unclear. We here report a multilevel analysis of auditory function across three disease-transmitting mosquitoes (Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus). All ears tested display transduction-dependent power gain. Quantitative analyses of mechanotransducer function reveal sex-specific and species-specific variations, including male-specific, highly sensitive transducer populations. Systemic blocks of neurotransmission result in large-amplitude oscillations only in male flagellar receivers, indicating sexually dimorphic auditory gain control mechanisms. Our findings identify modifications of auditory function as a key feature in mosquito evolution. We propose that intra-swarm communication has been a driving force behind the observed sex-specific and species-specific diversity.

Objective: To provide an overview of biotechnology and pharmaceutical companies active in the field of inner ear and central hearing disorders and their therapeutic programmes.Methods: Scoping search of scientific and grey literature using broad search terms enabling data extraction on base of company and its therapeutic programme, its lead indications, products, targets, mechanisms of action and current phases of clinical development.Results: A total of 43 biotechnology and pharmaceutical companies have been identified that are developing therapies for inner ear and central hearing disorders.Their programmes include drug-, cell-and gene-based approaches to prevent hearing loss or its progression, restoring hearing and regenerating the inner ear. Their therapeutic targets and specific mechanisms of action are wide-ranging, reflecting the complexity of the hearing pathways and the diversity of mechanisms underlying inner ear disorders. Whilst none of the novel products under investigation have yet made it to the clinical market, and a large proportion are still at preclinical phase, many therapies have already entered clinical testing with more expected to do so in the next few years. Conclusion:A wide range of novel therapies targeting different hearing, balance and tinnitus pathways and patient populations are approaching the clinical domain. It is important that clinicians involved in the care of patients with hearing loss prepare for what may become a radically different approach to the management of hearing disorders, and develop a true understanding of the new therapies' mechanisms of action, applications and indications.