Disposable surgical masks best for speeches

The researchers used a special loudspeaker shaped like a human head so that sound radiates as it would coming from a human mouth.

New York: Disposable surgical masks offer the best option in ensuring that you are being heard clearly when speaking, says a study that tested how different types of masks affect the acoustics of speech.

For the study, published in The Journal of the Acoustical Society of America, 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 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,” said Ryan Corey from University of Illinois at Urbana-Champaign in the US. “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.

Their data showed that all masks muffle the quiet, high-frequency sound generated when a person pronounces consonants.

The study found that disposable surgical masks offer the best acoustic performance among all tested, Corey said. Loosely woven 100 per cent cotton masks also perform well but, as shown in a study by other Illinois researchers, they may not be as effective as surgical masks at blocking respiratory droplets.