The Deaf and the Mute: Are they Held Accountable for their Deeds

Question :

Is the deaf-mute child responsible in the Shari'ah sense to perform acts of worship, such as the prayer? Or is he excused?

Answer:

When the deaf-mute child reaches puberty, he is obligated to perform the prayer and all of the other Islamic duties. This is based on general evidences, which indicate that the person who reaches puberty becomesvresponsible to perform all Islamic duties, as long as he is sane.
Bulugh (puberty or the coming of age) happens either, after fifteen years are completed, after the discharge of semen accompanied by pleasure either during a dream outside of a dream or after the growth of pubic hair; for the woman there is an added fourth sign: menstruation. The guardian of the deaf-mute child should teach him what he needs to know, for Allâh Almighty says:
"So keep your duty to do Allah and fear Him as much as you can."

The Prophet ﷺ said:
"I order you to do something, then do of it what you can."

"If The sane Muslim, who comes of age, even though he may be deaf or mute, must fear Allâh by doing what He ordered and by abstaining from what He forbade; the deaf-mute person should learn the essentials of his religion by the written word or by signs. And with Allah is the facilitation to do what is right.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 8 Pages 341-342