Workers for Canadian Hearing Services have been on strike since Monday across Ontario.
There are picket lines at nine CHS locations across the province, and at six MPP constituency offices.
According to a news release, the last time this workforce went on strike, they were out for 10 weeks in 2017.
"This small group of workers has an outsized impact, delivering critical programs for thousands of Deaf and hard of hearing Ontarians," an unidentified CUPE rep is quoted in an online news release.
CTV has reached out to CUPE for details on the negotiations stumbling blocks.
Locations closed indefinitely
According to a news release on the CHS website, the two sides have been negotiating for "several months" to renew a contract that expired March 31.
CHS says they offered staff a one-year collective agreement with a 4.9 per cent increase in pay.
CUPE, according to CHS, is asking for an increase of 30.5 per cent over three years.
"As we navigate the strike alongside the complexities of the current economic and political climate, we remain focused on resolving the labour dispute in a way that ensures stability for our staff and vitally essential services for our clients," the news release reads.
The company says audiology clinics are now closed but they will provide other services on a priority basis.