Researchers have published the results of a new study evaluating the acoustic effects of face masks on speech. The team tested medical masks, disposable surgical masks, masks with clear plastic windows around the mouth, and homemade and store-bought cloth masks made of different fabric types and numbers of layers.

Corey, an electrical and computer engineering postdoctoral researcher under professor Andrew Singer at the University of Illinois Urbana-Champaign, leads a team that studies audio signal processing, especially for listening devices like hearing aids. The results of the team’s new study evaluating the acoustic effects of face masks on speech are published in The Journal of the Acoustical Society of America.

«Previous research performed on this subject has focused on medical masks worn in health care settings,» Corey said, «But no one has looked at the acoustic effects caused by different kinds of fabric masks, so that’s where I focused our study.»

The team tested medical masks, disposable surgical masks, masks with clear plastic windows around the mouth, and homemade and store-bought cloth masks made of different fabric types and numbers of layers.

The researchers used a special loudspeaker, custom built by School of Art and Design graduate Uriah Jones and shaped like a human head so that sound radiates as it would coming from a human mouth.

«We put the different masks onto the head-shaped loudspeaker and played the same sound for every test,» Corey said. «We also placed the speaker onto a turntable to add a directional component to our data.»

The team collected data from a mask-wearing human speaker, as well.

Story Source: Materials provided by University of Illinois at Urbana-Champaign, News Bureau. Original written by Lois Yoksoulian. Note: Content may be edited for style and length.