To him who has ears to hear.
The koine akouō points to an endowment of hearing. Out of that God given akouō comes understanding and perception.
In the Revelation, 2:11 & 2:17 & 2:29 each instance uses the koine akouō.
Endued with the faculty of hearing.
Not deaf.
To attend & consider.
To understand & perceive.
Are your ears awake? Listen. Listen to the wind words, the Spirit blowing through the churches. ~MSG