In January 2022, a unique and extraor-dinary device by Rion was exhibited at the Consumer Electronics Show (CES) in Las Vegas, US, the world’s largest technology trade show. Named the Binaural Hearing Assist Device, this concept model is expected to provide functions for improving speech percep-tion in noisy environments and in multi-person conversations. Based on the Wear Casually theme, the design of the model focuses on lowering the psy-chological barriers to wearing such devices. We interviewed Dr. Yoichi Fujisaka of the Technical Development Center, who was involved in developing this concept model, about the functions and features developed to achieve more natural hearing.—What is a Binaural Hearing Assist Device?Fujisaka: According to a report (*1 ) issued by the Bluetooth SIG (Special Interest Group), Juniper Research (UK) denes assistive hearables as “hearing assist devices that have the primary purpose of providing hearing support.” My understanding is that there’s no unani-mous agreement on the precise denition just yet, as this can include support provided by other devices, like smart-phones. It’s not limited to the assistance provided solely by the device itself. New competing brands are releasing prod-ucts and soware developed with an eye on the OTC hearing aids rule to be eected in the US. ese dier from existing hearing aids, and their features are quite diverse. Some are based on a device that measures the user's hearing level, then perform multi-channel fre-quency analysis of the sound entering the microphone using a signal proces-sor, then calculate gain based on sound amplitude and hearing level to recon-gure and output the optimal sound for the user. Others use only a single chan-nel for frequency analysis to ensure tolerable processing delays (*2 ). Some forego frequency analysis altogether and control just the sound equalization process. But in all these cases, Binaural Hearing Assist Devices can be consid-ered as loosely dened devices built to specications that reect the concept of each brand.—What were some technical features and built-in functions of the device presented in this exhibition?Fujisaka: One technical feature is a bin-aural signal processing function that preserves the spatial impression of the sound. To enable the exchange of binau-ral signals with low processing delays, the two earbuds are connected by wire. is design made our device the world’s rst Binaural Hearing Assist Device to be equipped with a beamformer with a broad-side microphone array for front and le-right directional sound acquisi-tion. Beamforming employs an antenna array and microphone array to suppress unwanted disturbing signals by provid-ing directivity in the desired signal direction. Conventional hearing aids have already implemented delay and sum beamforming with end-re micro-phone arrays to acquire sound from the front. But even though the setup improves the signal-to-noise ratio of the target sound from the front, it degrades low-frequency components and adve-rsely aects the spatial impression of the sound, most notably distance per-ception. e beamformer in our new Binaural Hearing Assist Device uses the Minimum Variance Distortionless Response (MVDR) method, which allows distortionless acquisition of the target sound while preserving spatial impressions. In other words, sound is acquired as a binaural signal, not a monaural signal, as with sound source separation technology. I believe this holds signicant value. In addition, our device incorporates binaural wind noise suppression (the result of joint research with National College of Institute of Technology, Kumamoto College) as a binaural signal processing function that also helps preserve spatial impressions. e device oers unprece-dented comfort for daily wear.e following is a list of the func-tions featured in the device:• Side-branch type analysis and syn-thesis with short processing delays (Fig.1 )• 17-channel Wide Dynamic Range Compression (WDRC) (*3 )• Active noise cancellation• MVDR beamformer• Binaural wind noise reduction• Binaural impact noise reductionWhat are Hearing Assist Devices?Everyone wants to live their lives without giving a second thought to hearing sounds naturally.The Binaural Hearing Assist Device currently being developed by Rion may be the dream device that makes this possible for everyone.We interviewed the person in charge of developing this device, which was unveiled at a US exhibition, to learn about its functions and possibilities.A Futuristic Device to Help Rediscover the Joy of Conversation Yoichi Fujisaka, Doctor of InformaticsHearing Care, Sound and Vibration Measure-ment Technology Development Group, R&D Department, Technical Development Center. After working at the National Institute of Mental Health and then at the National Institute of Advanced Industrial Science and Technology, he joined Rion in 2006. He was placed in charge of the development of the RUHQ series, Rion’s rst remotely controllable hearing aids. He’s worked on developing hearing aid processing algorithms and auditory perception studies.*1 : Market Research Note: Assistive Hearables, September 2020 URL:https://www.bluetooth.com/wp-content/uploads/2020/09/MRN-Assistive-Hearables.pdf*2 : Tolerable processing delay refers to a delay that can be tolerated without discomfort in real-time communication between the movement of the speaker’s mouth and the sound received from the device or between the sound of one’s own voice as perceived by the ear via bone conduction and that received from the device.*3 : The WDRC function determines the gain needed to produce optimal loudness of sound for the user by controlling loudness by frequency so that the sound falls within the user’s audible range estimated based on his or her hearing acuity.IN THE BACKYARDOn the Front Lines of Technology 12What are Hearing Assist Devices?A Futuristic Device to Help Rediscover the Joy of Conversation
元のページ ../index.html#14