Normal-hearing people use sound as a cue to recognize various events that occur in their surrounding environment; however, this is not possible for deaf and hearing of hard (DHH) people, and in such a context they may not be able to freely detect their surrounding environment. Therefore, there is an opportunity to create a convenient device that can detect sounds occurring in daily life and present them visually instead of auditorily. Additionally, it is of great importance to appropriately evaluate how such a supporting device would change the lives of DHH people. The current study proposes an augmented-reality-based system for presenting household sounds to DHH people as visual information. We examined the effect of displaying both the icons indicating sounds classified by machine learning and a dynamic spectrogram indicating the real-time time-frequency characteristics of the environmental sounds. First, the issues that DHH people perceive as problems in their daily lives were investigated through a survey, suggesting that DHH people need to visualize their surrounding sound environment. Then, after the accuracy of the machine-learning-based classifier installed in the proposed system was validated, the subjective impression of how the proposed system increased the comfort of daily life was obtained through a field experiment in a real residence. The results confirmed that the comfort of daily life in household spaces can be improved by combining not only the classification results of machine learning but also the real-time display of spectrograms.
Keywords: augmented reality; deaf and hard-of-hearing (DHH) people; dynamic spectrogram; environmental sound recognition; machine learning.