Heard

Acts 19:1-5 ESV

1 And it happened that while Apollos was at Corinth, Paul passed through the inland country and came to Ephesus. There he found some disciples. 2 And he said to them, Did you receive the Holy Spirit when you believed? And they said, No, we have not even heard that there is a Holy Spirit. 3 And he said, Into what then were you baptized? They said, Into John's baptism. 4 And Paul said, John baptized with the baptism of repentance, telling the people to believe in the one who was to come after him, that is, Jesus. 5 On hearing this, they were baptized in the name of the Lord Jesus.

The Thayer definition below for the Greek word translated here as "heard" implies a hearing that is beyond the natural understanding of our English meaning.  These disciples had responded to the word spoken by Apollos and were washed in the water of repentance, but words not united with the presence of the Holy Spirit can only bring us near to the life of God.  That water had not been turned to wine as happens when the Holy Spirit descends on the believer.

Like the blind man partially receiving his sight, they could dimly see into the kingdom of God, but vision was not totally restored.  They had not received life which only comes with the baptism into the very life of God.  

It is the Holy Spirit who enables us to see as best we can into the kingdom of God, and to experience the grace, peace, and power given to all who call on the name of Jesus with a humble heart.  Baptism in the Spirit brings the wine that fills the cup to overflowing.  We are able to experience the peace, power, and truth which comes from God.

KJV

    1  And it came to pass,that, while Apollos was at Corinth, Paul having passed through the upper coastscame to Ephesus: and finding certain disciples, 2 He said unto them, Have yereceived the Holy Ghostsince ye believed? Andthey said unto him, We have not so much as[+]heard whether there be anyHoly Ghost. 3  And he said unto them, Unto what thenwere ye baptized? Andthey said, Unto John’s baptism. 4  Then said Paul,John verily baptized with the baptism of repentance,saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus. 5  When they heard[apta G191 ἀκούω * akouō * ak-oo'-o * A primary verb; to hear (in various senses): - give (in the) audience (of), come (to the ears), ([shall]) hear (-er, -ken), be noised, be reported, understand. [LEX][TGD] ἀκούω
akouō
Thayer Definition:
1) to be endowed with the faculty of hearing, not deaf
2) to hear
2b) to attend to, consider what is or has been said
2c) to understand, perceive the sense of what is said
3) to hear something