Brain-Tech Startup neumo, Improving Hearing Loss by Training the Brain's 'Listening Ability,' Raises Series A Funding from Bio-Healthcare VC D3 LLC
neumo, a brain-tech startup developing the hearing training app 'Kikumoa,' has raised Series A funding from D3 LLC to advance clinical validation and expand its societal impact against hearing loss and dementia risks.
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- 📰 Published: April 23, 2026 at 19:30
- 🔍 Collected: April 23, 2026 at 11:01
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D3 LLC (Shibuya-ku, Tokyo; Managing Partner: Tomoya Nagata), a venture capital firm specializing in bio-healthcare, has subscribed to a third-party allocation of new shares in a Series A round by neumo Inc. (Shibuya-ku, Tokyo; Representative Director and CEO: Ryusei Wakabayashi; hereinafter 'neumo') through its managed funds.
A Team Running Since the Dawn of Brain-Tech
neumo is a pioneer in domestic brain-tech, established in 2017 when Mr. Wakabayashi and others, co-founders of the UI/UX consulting firm beBit, spun out of the company.
Since its founding, neumo has built trust as an expert in neuroscience through transactions with major research institutions such as the University of Tokyo, Kyoto University, Keio University, the National Institute of Advanced Industrial Science and Technology (AIST), and the Advanced Telecommunications Research Institute International (ATR), as well as major domestic pharmaceutical, IT, and manufacturing companies.
As a result of continuously exploring areas that can be implemented at the current scientific level and have significant social significance, neumo focused on the issue of 'hearing' associated with aging. This led to the development of the hearing training app 'Kikumoa.'
Hearing Training App 'Kikumoa': Training the 'Brain,' Not the Ears
The issue of hearing associated with aging is caused not only by the ears but also by the decline in the function of the brain that processes sound. It is estimated that there are two to three times as many people suffering from so-called 'hidden hearing loss'—where they can 'hear sounds but cannot catch the words'—as those diagnosed with hearing loss.
'I can hear the sound, but I can't catch the words'—The issue of hearing associated with aging stems not only from the ears but also from the decline in the brain's sound processing capabilities. Kikumoa is a training app that exercises this 'listening ability' of the brain using a smartphone. Based on neurofeedback technology, it activates the auditory cortex, frontal lobe, and brainstem.
In the initial PoC, the signal-to-noise (SN) ratio, which indicates hearing ability in noisy environments, improved by 3.1 dB. In addition, effects in daily life have been confirmed, such as 'no longer having to ask family members to repeat themselves' and 'being able to hear the TV even with the volume turned down.'
Even if someone feels anxious about their hearing, there was almost nothing they could do other than use hearing aids. Kikumoa is a new option that approaches the brain's listening ability, regardless of whether or not a hearing aid is used.
Great Expectations as a Promising Early Intervention Point in Dementia Prevention
neumo's efforts are also drawing attention from the perspective of dementia prevention. A review paper published in The Lancet in 2020 (Livingston et al., 2020) reported that hearing loss has the highest contribution rate (approximately 20%, estimated by the same paper) among preventable risk factors for dementia.
By the time Alzheimer's disease is diagnosed, neuronal loss has already progressed, and pharmacotherapy is limited to suppressing the progression. On the other hand, hearing loss often precedes the onset of dementia and is expected to be one of the few realistic early approaches that can intervene from the stage of 'hidden hearing loss.'
The WHO also clearly identified hearing loss as a risk factor for dementia in its 2019 guidelines. Social interest is rapidly increasing.
Emphasizing Science: Strong Collaboration with Academia
neumo is collaborating with academia to advance the validation of efficacy in actual clinical practice and the elucidation of the mechanism of action.
The company conducts research and development while receiving advice from world-leading neuroscientists, such as Center Director Hakwan Lau of the Center for Neuroscience Imaging Research at the Institute for Basic Science in South Korea (former tenured professor at UCLA) and Professor Talma Hendler of Tel Aviv University. Starting in the second half of 2025, a joint research project to measure the improvement effects on speech-in-noise perception and memory recall functions will be conducted with Keio University Hospital.
Creating Social Impact Through the Social Implementation and Application of Neuroscience
neumo's initiatives were also introduced as a startup contributing to solving social issues in Japan Post Insurance Co., Ltd.'s 'Responsible Investment Report 2025' (p. 84).
D3 LLC expects that neumo will bring a multi-layered social impact: (1) improving the QOL of people struggling with hearing, (2) reducing the number of patients with hearing loss and the burden on families and caregivers, and (3) reducing the long-term risk of dementia.
Comment from neumo Representative Director and CEO Ryusei Wakabayashi
The human brain has plasticity, which allows it to regain listening ability even as it ages. However, this scientific fact has not yet reached most people. Even if they feel anxious about their hearing, it ends with 'It can't be helped because of my age.'
Since its founding, neumo has been working to incorporate this plasticity into actual products.
Kikumoa is an app that trains the brain's sound processing using just a smartphone, without the need for special hardware. We have received feedback from people who continued the training, saying, 'It became easier to hear, so I invited a friend out for the first time in a while.' Hearing training is not just about numbers...
A Team Running Since the Dawn of Brain-Tech
neumo is a pioneer in domestic brain-tech, established in 2017 when Mr. Wakabayashi and others, co-founders of the UI/UX consulting firm beBit, spun out of the company.
Since its founding, neumo has built trust as an expert in neuroscience through transactions with major research institutions such as the University of Tokyo, Kyoto University, Keio University, the National Institute of Advanced Industrial Science and Technology (AIST), and the Advanced Telecommunications Research Institute International (ATR), as well as major domestic pharmaceutical, IT, and manufacturing companies.
As a result of continuously exploring areas that can be implemented at the current scientific level and have significant social significance, neumo focused on the issue of 'hearing' associated with aging. This led to the development of the hearing training app 'Kikumoa.'
Hearing Training App 'Kikumoa': Training the 'Brain,' Not the Ears
The issue of hearing associated with aging is caused not only by the ears but also by the decline in the function of the brain that processes sound. It is estimated that there are two to three times as many people suffering from so-called 'hidden hearing loss'—where they can 'hear sounds but cannot catch the words'—as those diagnosed with hearing loss.
'I can hear the sound, but I can't catch the words'—The issue of hearing associated with aging stems not only from the ears but also from the decline in the brain's sound processing capabilities. Kikumoa is a training app that exercises this 'listening ability' of the brain using a smartphone. Based on neurofeedback technology, it activates the auditory cortex, frontal lobe, and brainstem.
In the initial PoC, the signal-to-noise (SN) ratio, which indicates hearing ability in noisy environments, improved by 3.1 dB. In addition, effects in daily life have been confirmed, such as 'no longer having to ask family members to repeat themselves' and 'being able to hear the TV even with the volume turned down.'
Even if someone feels anxious about their hearing, there was almost nothing they could do other than use hearing aids. Kikumoa is a new option that approaches the brain's listening ability, regardless of whether or not a hearing aid is used.
Great Expectations as a Promising Early Intervention Point in Dementia Prevention
neumo's efforts are also drawing attention from the perspective of dementia prevention. A review paper published in The Lancet in 2020 (Livingston et al., 2020) reported that hearing loss has the highest contribution rate (approximately 20%, estimated by the same paper) among preventable risk factors for dementia.
By the time Alzheimer's disease is diagnosed, neuronal loss has already progressed, and pharmacotherapy is limited to suppressing the progression. On the other hand, hearing loss often precedes the onset of dementia and is expected to be one of the few realistic early approaches that can intervene from the stage of 'hidden hearing loss.'
The WHO also clearly identified hearing loss as a risk factor for dementia in its 2019 guidelines. Social interest is rapidly increasing.
Emphasizing Science: Strong Collaboration with Academia
neumo is collaborating with academia to advance the validation of efficacy in actual clinical practice and the elucidation of the mechanism of action.
The company conducts research and development while receiving advice from world-leading neuroscientists, such as Center Director Hakwan Lau of the Center for Neuroscience Imaging Research at the Institute for Basic Science in South Korea (former tenured professor at UCLA) and Professor Talma Hendler of Tel Aviv University. Starting in the second half of 2025, a joint research project to measure the improvement effects on speech-in-noise perception and memory recall functions will be conducted with Keio University Hospital.
Creating Social Impact Through the Social Implementation and Application of Neuroscience
neumo's initiatives were also introduced as a startup contributing to solving social issues in Japan Post Insurance Co., Ltd.'s 'Responsible Investment Report 2025' (p. 84).
D3 LLC expects that neumo will bring a multi-layered social impact: (1) improving the QOL of people struggling with hearing, (2) reducing the number of patients with hearing loss and the burden on families and caregivers, and (3) reducing the long-term risk of dementia.
Comment from neumo Representative Director and CEO Ryusei Wakabayashi
The human brain has plasticity, which allows it to regain listening ability even as it ages. However, this scientific fact has not yet reached most people. Even if they feel anxious about their hearing, it ends with 'It can't be helped because of my age.'
Since its founding, neumo has been working to incorporate this plasticity into actual products.
Kikumoa is an app that trains the brain's sound processing using just a smartphone, without the need for special hardware. We have received feedback from people who continued the training, saying, 'It became easier to hear, so I invited a friend out for the first time in a while.' Hearing training is not just about numbers...