Jeremiah 25 says, "The Lord shall roar from on high, and utter his voice from his holy habitation; he shall mightily roar upon his habitation; he shall give a shout, as they that tread the grapes, against all the inhabitants of the earth. A noise shall come even to the ends of the earth" and 1 Thess 4 and 1 Cor 15 both mention the trumpet blast.

Is there any scripture indications that the world wide blast will not be heard by everyone, but only those caught up in the rapture?  Yes, there are indications for this belief that the rapture may appear to be silent for those left behind, and not silent for those who are raptured.

In Revelation 2 & 3, a phrase is repeated SEVEN TIMES: "He that hath an ear, let him hear what the Spirit saith unto the churches".  This indicates that not everyone has an ear to hear, doesn't it?

When Stephen was preaching to the Pharisees in Acts 7, they refused to see and hear.  Did they see Jesus as Stephen saw?  The text does not say.  It implys, however, that because Stephen was full of the Holy Ghost, he saw what he saw.  And it does say they "stopped their ears".

54 When they heard these things, they were cut to the heart, and they gnashed on him with their teeth.
55 But he, being full of the Holy Ghost, looked up stedfastly into heaven, and saw the glory of God, and Jesus standing on the right hand of God,
56 And said, Behold, I see the heavens opened, and the Son of man standing on the right hand of God.
57 Then they cried out with a loud voice, and stopped their ears, and ran upon him with one accord,

In John 5 it strongly implies two different resurrections.  The first is for "they that hear", verse 25, and the second is for "all that are in the graves shall hear", verse 28.

25 Verily, verily, I say unto you, The hour is coming, and now is, when the dead shall hear the voice of the Son of God: and they that hear shall live.
26 For as the Father hath life in himself; so hath he given to the Son to have life in himself;
27 And hath given him authority to execute judgment also, because he is the Son of man.
28 Marvel not at this: for the hour is coming, in the which all that are in the graves shall hear his voice,
29 And shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation.

In John 10, it says repeatedly that the sheep hear the voice of Jesus.  This implies that those who are not the sheep, do not hear the voice of Jesus.

John 10:3 To him the porter openeth; and the sheep hear his voice: and he calleth his own sheep by name, and leadeth them out.
John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.
John 10:27 My sheep hear my voice, and I know them, and they follow me:

Now, let's examine this "trumpet voice" of the rapture more closely, in two translations: KJV first, and then NIV.

1 Thess 4:16 For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: KJV

16 For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. NIV

In the KJV it says "shout".  In the NIV it says "loud command".

In Rev 4:1, it also appears to be a command, "come up hither...".

Revelation 4:1 After this I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter.

The inherant quality of a command is that some will not obey.  If people today refuse to hear God's commands, why should we assume that the unsaved will hear the trumpet voice command of the pretribulation rapture?

Along this same theme, there are verses which imply that Jesus WILL NOT be seen by everyone, BUT ONLY TO THE BLESSED, THE PURE IN HEART, THOSE WHO BELIEVE, AND UNTO THEM THAT LOOK FOR HIM.  And this is in contrast to the second coming, when Jesus WILL be seen by everyone.

Matthew 5:8 Blessed are the pure in heart: for they shall see God.

John 11:40 Jesus saith unto her, Said I not unto thee, that, if thou wouldest believe, thou shouldest see the glory of God?

Hebrews 9:28 So Christ was once offered to bear the sins of many; and unto them that look for him shall he appear the second time without sin unto salvation.

Finally, in 2 Thess 2, Paul says that God will send a strong delusion for those who do not love the truth.

2 Thessalonians 2:11 And for this cause God shall send them strong delusion, that they should believe a lie:

It is very possible, and there is abundant scriptural support for the idea as we have seen, that the unsaved will neither see Jesus, nor hear him, in the pretribulation rapture, whereas the saved will both hear the world wide trumpet voice command and will see Jesus coming down from heaven.  Here are some more incidents in the Bible to think about on this matter.

In Numbers 22:23, Balaam's donkey saw the angel, when at the same time, Balaam himself did not see the angel.

In Acts 9, Saul became Paul when he saw Jesus on the road to damascus.  The men traveling with Saul did not have Saul's full perception of the event.

Acts 9:7 And the men which journeyed with him stood speechless, hearing a voice, but seeing no man.

To say that God cannot act in a way in which only some will see, and only some will hear, is 100% directly contrary to what scriptures teach.  Not only can God give a command that only his sheep will hear, but there is abundant scriptural evidence which supports the position.

In fact, to boldly assert that all people will hear His trumpet voice command at the rapture is NOT consistent with John 5, "they that hear shall live", or John 10, "My sheep hear my voice".

This likely silent & unseen (to the unsaved) coming at the pretribulation rapture is only one of the many contrasts that exist between the rapture and second coming.  The attempted attack on this one single difference, even if valid, and we have seen that it is not valid, does not have anything to say about all the other differences, and thus, does not even remotely begin to disprove the pretribulation rapture.