KITCHENER -- Masks will be mandatory in all indoor public spaces starting on Monday.

But for people who are deaf or hard-of-hearing, masks can pose a barrier to communication.

Canadian Hearing Services said it's an invisible disability.

"For someone with hearing loss, day-to-day communication can cause frustration, can cause anxiety," said Rex Banks with the service.

Anthony Cashin and his daughter, Antoinette, understand the frustration. Anthony is deaf.

"Many times he gets fed up and it's hard to understand," Antoinette Cashin explained.

Antoinette often travels with Anthony to act as a translator. Without her, mandatory masks would make it impossible for deaf people to know what another person is saying.

"They can't read their lips or their facial expressions," Antoinette said.

The mandatory mask bylaw comes into effect on July 13. Face coverings must be worn in indoor public spaces and on public transit. People who are deaf or hard of hearing are exempt from the bylaw, as are their translators if they have one.

Some businesses are already encouraging the new rule.

Cambridge resident Kimberly Gawne identifies as hard of hearing and doesn't wear a mask.

"I can only imagine how isolated people who are fully deaf feel right now." Gawne explained.

Gawne said she needs to be within a foot-and-a-half of people to be able to hear them properly, which isn't ideal during a time of physical distancing.

"I use of combination of reading lips and hearing someone in order to actually hear them," Gawne said.

However, that's much more difficult if people are wearing masks.

"You're going to reduce the output of sound by three to five decibles, which is as much of about 25 per cent reduction," Banks said.

The Cashins said face shields may be more helpful, offering a clear view of mouths and expressions.

"To show if they're happy, sad or mad or something," Antoinette said.

The region's website said face shields aren't a substitute for masks, since they don't protect others from respiratory droplets. However, the region added shields are better than nothing if people aren't able to cover their face with a mask.