Toward a framework for objective certification of public address quality in general public spaces

In Japan, public address announcements for life-threatening evacuation guidance are regulated by legally binding standards, ensuring minimum quality. However, for general public address announcements, various speech intelligibility indices have been proposed and standardized, but their application in public spaces is optional. Moreover, in spaces such as stations, airports, and commercial facilities, few criteria for these indices have been defined. Thus, even if measured, it is difficult to objectively determine whether the sound quality is adequate. Consequently, the skills of manufacturers, designers, and installers involved in public address systems are not appropriately recognized in terms of acoustic quality. Similarly, owners of public spaces cannot assess whether the announcement quality in their facilities is sufficient. Although these indices can be predicted through simulations and designers propose systems based on these predictions, owners with limited acoustic knowledge may find it difficult to judge their reliability. This often results in hesitation to adopt costly systems, and many public spaces end up with low-quality announcements. While evaluation indices exist, their meaning is not widely understood socially and has not led to quality improvement. This presentation discusses the introduction of a certification framework and an independent third-party certifying body for general public address announcements to improve quality and contribute to creating more comfortable public spaces.