How much COVID-19 face protections influence speech intelligibility in classrooms?

Area of Science:

• Acoustics
• Public Health
• Education

Background:

• The COVID-19 pandemic necessitated widespread use of personal protective equipment, including face masks.
• Face masks, while crucial for preventing aerosol spread, can impede speech transmission and clarity.
• The mandatory or recommended use of face masks by educators impacts students' ability to comprehend lessons.

Purpose of the Study:

• To investigate the effects of various face protection types on speech transmission in classroom environments.
• To quantify the impact of face masks on sound pressure levels and speech intelligibility.
• To analyze how different mask typologies influence the indoor sound field and source emission characteristics.

Main Methods:

• An experimental campaign was conducted in a classroom setting with varying reverberation conditions.
• Speech transmission and sound pressure levels were measured at multiple receiver positions.
• A microphone array was employed to analyze the spatial distribution of the indoor sound field relative to the sound source.

Main Results:

• Different types of personal protective equipment demonstrably affect speech transmission and sound pressure levels.
• The impact is particularly noticeable at mid-to-high frequencies.
• The emission lobes of the sound source were observed to vary when subjects wore certain types of personal protective devices.

Conclusions:

• Face masks significantly alter acoustic conditions within a classroom, impacting speech intelligibility.
• The type of face mask worn influences the degree of speech transmission degradation.
• Understanding these effects is crucial for optimizing communication in educational settings during pandemic conditions.