Improved face-worn PPE designs for use by the public and professionals to reduce audio-visual communication difficulties

To reduce the transmission of COVID-19, personal protective equipment (PPE) is required. PPE to protect the eyes, nose and mouth comprises face masks and transparent visors. These range from a simple covering made from domestic fabrics for use by the public, to FFP3/N99 rated air filters and wrap-around face visors in care settings. All these PPE styles make spoken and signed communication harder. Everyone, not just the hearing impaired, will struggle to understand in real-world conditions and background sounds. This will result in increased listening effort, stress, communication errors and potentially social withdrawal. Articles published in May 2020 by the PI and his group leader in a professional journal (https://www.entandaudiologynews.com/features/audiology-features/post/the-challenges- of-facemasks-for-people-with-hearing-loss) produced over 100 responses from anxious adults, parents, public and professionals. Both acoustic and visual cues are reduced by face coverings: (i) acoustic : the high frequencies of the sound are attenuated, leading to a "muffled" perception (ii) visual : sight of the talker's mouth movements that can be used by all listeners to supplement the muffling of speech and (iii) visual : full-facial expressions that convey emotions, supplement lip-reading and are essential components of (the non-acoustic) British Sign Language (BSL). Employing user surveys, fabrication, and testing, this project will produce validated examples of facemask and visor designs that preserve acoustic and visual cues thereby offering less effortful communication in a variety of usage scenarios. It brings together acousticians, audiologists, material scientists, and users to tackle an urgent problem that affects everyone now, and will also outlast the current pandemic.