He did speak audibly to Israel when He gave them the Ten Commandments, and the Bible says that Israel was so fearful at what they saw and heard, they pleaded that He no longer speak to them (see Exod. 20:18,19; Heb. 12:19).
When He spoke on the Mount of Transfiguration, He terrified the disciples (see Matt. 17:5,6). When He once spoke audibly to Jesus, the people thought that they heard thunder (see John 12:28,29). So why didn’t God just whisper on these occasions? Perhaps He did.
However, God (in His infinite wisdom) has chosen what the Bible calls “the foolishness of the mes- sage preached” to bring the gospel to humanity (see 1 Cor. 1:21). He has condescended to use lowly man to deliver the message of everlasting life to dying humanity.
When it comes to God speaking to us, it is important to make sure that we don’t exaggerate our im- portance. We are but very tiny specks on a tiny speck of a planet, moving through the massive infinitude of space. If you want a special audience with the President, he likely will not come running to speak es- pecially to you when, how, and where you want. Only a person with delusions of grandeur indeed would expect such treatment.
How much more so with the Creator of the universe? You are not going to get a special audience with God. So humble yourself, repent of your sins, and trust the Savior, then seek God through prayer and reading of His Word. Prayer is you speaking to God, and the Bible is God speaking to you. Make sure you listen carefully to what He says. Your eternity depends on it.
Hebrews 12:25 "See that you do not refuse Him who speaks. For if they did not escape who refused Him who spoke on earth, much more shall we not escape if we turn away from Him who speaks from heaven..."