He opens their ears and terrifies them with warnings
Job had complained that God kept him wholly in the dark concerning the meaning of his dealings with him, and therefore concluded he dealt with him as his enemy. "No," says Elihu, "he speaks to you, but you do not perceive him; so that the fault is yours, not his; and he is designing your real good even in those dispensations which you put this...
Commenting on Job 33:14-18
Then he openeth the ears of men,.... Not the ears of his body, which remaining shut while things are presented to his mind in a dream or vision, but his internal ears; it is the same with opening the heart or understanding to attend to and receive the things delivered in this visionary way: and sealeth their instruction; sends home the instruction given in this...
Literally, "sealeth (their ears) to Himself by warnings," that is, with the sureness and secrecy of a seal He reveals His warnings [UMBREIT]. To seal up securely (Job 37:7).