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Research paper : Development and standardization of accessible design technologies that address the needs of senior citizens (K. Kurakata, et al.)−21−Synthesiology - English edition Vol.1 No.1 (2008) method cannot be used in actual design practice where cost reduction and speed are crucial (also, the designer may not necessarily be a specialist on hearing or vision). Complex model and method, in general, narrow the range of application. To propagate accessible design, it must be used in various products transcending the barriers of product category. How much the method can be simplified without limiting the application range yet maintaining design accuracy is the most challenging issue in the standardization of accessible design technology (Arrow ④ ).Simplification of the model can be done by trial and error, but it is necessary to employ the basic findings of human property (product of Type 1 Basic Research). In case of auditory signals, it was necessary to simplify the auditory model on hearing auditory signals in noise (Section 4.1). However, it is impossible to study the auditory effect of all fluctuating sound. The model was simplified and experimentally verified, so the ease of hearing could be determined by the volume ratio between noise and auditory signals (SN ratio) by reviewing the general findings of various basic researches on hearing characteristics (Type 2 Basic Research).7 Future issues in the standardization of accessible design technology7.1 Accommodating new auditory signals and voice guideWith the establishment of JIS S 0013 and 0014, the standardization of basic specifications for auditory signals for consumer products is almost complete. However, requests for new standardizations are being placed by the industry, as auditory signals become prevalent.First concerns auditory signals with complex acoustic structure. Current JIS addresses relatively simple sound with constant frequency and volume as subject of standardization. However, with the advance and diffusion of new technology represented by the ringing melody of cell phones, there is interest in using complex musical sound as auditory signals. Second pertains to the use of voice. Products using voice guide instead of simple auditory signals are expected to increase, to communicate more information such as operating instructions to the users.JIS S 0014 simplified the design method as much as possible, so designers who are not hearing or acoustic specialists can use it. However, authors have received comments that it is still “difficult”. Major issue for the future is to develop current JIS into a method that can address more acoustically complex auditory signals and voice guide without increasing the complexity of the procedure.7.2 Development of international standardFortunately, JIS Guidelines for the Elderly and People with Disabilities have been employed in designs of many products intended for accessible design. ISO standardization is currently in progress as a step in domestic standardization for guidelines including JIS S 0014 [17]. Like the volume setting method discussed in this paper, the design methodology based on basic human perception property is applicable, in principle, to products of any country. Accessible design technology is expected to be used effectively in countries other than Japan where birthrate is decreasing and the aging population is increasing.In conjunction with international standardization, the authors are encouraging the standard setters to cite these standards in other product standards to widely propagate accessible design technology. Accessible design technology should become common regardless of the product type or country of production. That is because even if the product is well designed and elderly-friendly, it is inconvenient for the users if non-compatible designs coexist.Careful manufacturing to match user characteristic and demand is the stronghold of Japanese corporations. If Japanese industry can lead the world market in the field of accessible design, Full Research can be called successful.AcknowledgementsMuch of JIS Guidelines for the Elderly and People with Disabilities, for which the authors created the draft, are based on the results of foundational research conducted jointly with the National Institute of Technology and Evaluation (NITE). Particularly, the cooperation of NITE was essential in conducting large-scale measurement for perception property of the elderly. We express our gratitude to all people who cooperated.Fig. 7 Steps of accessible design technology development presented in comparison with conventional human science study.??①②③④Current productTo Type 2 Basic Research・ Research to clarify mechanism based on data for small number of subjects・ Average human beingType 1 Basic Research・ Research to describe distribution based on data for large number of subjects・ Emphasis on individual difference including aging changeTo Type 2 Basic Research・ Improvement of design accuracy by intricate model and complex methodType 1 Basic Research・ Generalization of method・ Simplification of environmental conditionAccessible design product

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