Most hearing loss is caused by the death or damage to the sensory cells in the cochlea. This is called sensorineural hearing loss, and this makes up an estimated 90% of all hearing loss in humans.

These hair cells and auditory neurons are very easy to damage through exposure to  noise, certain chemicals, or just as a natural consequence of ageing. These cells cannot be repaired or regenerate in humans. They develop in utero: you are born with a compliment that you must retain for your entire life. If you lose them, you lose hearing function and therefore progressive loss results in progressive deafness.

Most patients suffer from damage to the auditory hair cells. This makes up roughly 75% of the sensorineural hearing loss population. Initially, Rinri is focused on repairing damage to the auditory neurons who make up about 25% of the population. In these patients hearing loss results from the inability of the cochlea to effectively transmit signals from the hair cells to the brain.

Patients with hearing loss related to auditory neuron function are particularly badly served by current healthcare practice and solutions. Hair cell damage can be partially circumvented by the use of hearing aids and cochlear implants. Hearing aids are sound amplifiers that take sound and amplify frequencies which are useful for the perception of human speech. Cochlear implants are cochlear stimulation devices, which detect the sound from the environment, convert it to electrical signals, and then send a signal the cochlear implants electrode array, effectively bypassing the damaged hair cells to directly stimulate the auditory neurons. If your auditory neurons are damaged or absent, then these medical devices will not work well because you need the auditory neuron population to form the  connection between the cochlea and the brain.

Rinri is working closely with patients who suffer from hearing loss and their family members to inform the work that we are carrying out. An important part of this is understanding patients’ needs and their thoughts on Rinri’s cell therapy. Discussions with patients have revealed that there is considerable patient demand and need for a treatment that restores natural hearing without the need for hearing devices such as hearing aids and cochlear implants. Specifically, patients have expressed that hearing devices are “very limited” and that “normal hearing is totally different from a cochlear implant and would be wonderful…and unbelievable”. They feel that it “takes an awful lot of work to hear and recognise sounds again” with a cochlear implant. Rinri have found that patients would like to have access to the full range and complexity of sound, that they would like to experience the joys of music and participate in group conversations; these are benefits that not even the very best hearing devices can guarantee. In addition, parents of deaf children have expressed that a hearing restoration cell therapy would be “amazing” and is the “ultimate goal” for their children, especially since we live in a hearing world. They have further highlighted that natural hearing would “massively enhance life” for children who have additional needs.