To be sure, the article is not specific about if these dilsiz were actually deaf or not, it may as well refer to people who were vowed to be silent or who had their tongue cut off in order to work at the court. But I guess at least some of them must have been deaf.
Polyglot City is the right instance for you, if you're interested in languages, language learning and translating, or if you are multilingual or polyglot. All languages are allowed to flourish on our timelines. Welcome!