Here's why:
* Hearing impairments existed: People with hearing impairments existed throughout history, and they would have needed ways to communicate.
* Gestures were used: Throughout history, people have used gestures to communicate, especially when verbal communication was difficult or impossible (e.g., in noisy environments, across distances).
* Sign language was used in monasteries: Some monasteries used signs and gestures to communicate in silence, especially during periods of prayer or contemplation.
However, there's no evidence of a widespread, codified sign language system like we have today.
Here's why it's difficult to know for sure:
* Lack of written records: Medieval sign language would have been mostly oral and gestural, making it difficult to preserve in written records.
* Limited documentation: Records that do exist are often fragmentary and don't provide a complete picture of communication practices.
In summary: While we can't say for certain that there was a formalized sign language in medieval times, it's highly probable that people with hearing impairments used a variety of gestures and signs to communicate. It's important to remember that the history of sign language is still being researched and documented.