It’s interesting that it took Eli three times to realize that the Lord was calling.
This may be because it was late and he had been sleeping. Or, it may be because the word of the Lord was rare in those days and visions were infrequent (v 1). Or, it may be because Eli was ministering without a “current” relationship with God.
Whatever the reason, he was familiar enough with the way that God speaks that he knew it was the Lord speaking. He also knew from his own experience how to hear God’s voice and how to help Samuel to hear God’s voice.
I think that it’s easy for me to be “familiar” with how to hear God’s voice, and at the same time to not actually be listening to what He is saying to me. I can rely on a past relationship with God rather than a “current” relationship. [Past relationship may mean last week last month, or even yesterday.]
I choose to seek to listen to God’s voice today. I choose to live in a “current” relationship with God today.