In Luke 1 (ESV), Zechariah the priest is rendered mute for his lack of faith:
19 And the angel answered him, “I am Gabriel. I stand in the presence of God, and I was sent to speak to you and to bring you this good news. 20 And behold, you will be silent and unable to speak until the day that these things take place, because you did not believe my words, which will be fulfilled in their time.” 21 And the people were waiting for Zechariah, and they were wondering at his delay in the temple. 22 And when he came out, he was unable to speak to them, and they realized that he had seen a vision in the temple. And he kept making signs to them and remained mute.
The word for mute in verse 22 is κωφός, which in this form is used four times and is always translated mute. (But note the usage of κωφοὶ, which is rendered deaf twice).
Later in Luke 1, it appears that Zechariah is indeed deaf:
62 And they made signs to his father, inquiring what he wanted him to be called.
Why would you have to make signs if he can hear you speaking?
Thus, my question: in NT Greek, does the word κωφός necessarily carry the meaning of deafness? Or is that a possible but not necessary implication? Or do we assume Zechariah was deaf merely on the basis of verse 62?