In a dream, listening to the Quran, or to praise of the Prophet (may God bless him and grant him peace), or listening to a sermon, signifies guidance, turning in repentance to God the Exalted, and returning to Him, glory be to Him. If he listens to something other than that, he is like those of whom God the Exalted said:
وَإِن تَدْعُوهُمْ إِلَى ٱلْهُدَىٰ لَا يَسْمَعُوا۟ ۖ وَتَرَىٰهُمْ يَنظُرُونَ إِلَيْكَ وَهُمْ لَا يُبْصِرُونَ
“And if you invite them to guidance, they do not hear; and you see them looking at you while they do not see.”
Quran 7:198 · Saheeh International
Eavesdropping is lying and tale-bearing, and the eavesdropper may suffer harm from the ruler.
Whoever sees that he is listening: if he is a merchant, he will ask for a sale contract to be cancelled; and if he is a governor, he will be removed. If he sees that he is listening in on a person, he wants to expose that person's secrets and disgrace him.
Whoever sees that he listens to various sayings and follows the best of them will receive glad tidings.
Whoever sees that he hears but pretends that he does not hear is lying and will make a habit of it. Consider the sounds heard in a dream and give the dreamer what suits him of them: the clamor of human beings is provision and benefits; the sounds of livestock are worries, troubles and fears; the neighing of horses is honor and strength; the barking of a dog is talk and meddling in what does not concern one; the cry of the cheetah is indications and arrogance; the cooing of pigeons is lamenting or marriage; the twittering of the swallow is useful speech or listening to the Quran; the croaking of the frog is beating, or the sound of watchmen; the hissing of the viper is fighting, scheming and warning; the braying of the donkey is invoking curses on the oppressors; the braying of the mule is talk and wading into doubtful matters; the lowing of the calf is civil strife (fitna); the grumbling of the camel is travel, fatigue and toil; the roaring of the lion is arrogance and threats; the mewing of the cat is clamor, tale-bearing, backbiting and slander; the squeaking of the mouse is gathering, friendship and provision; the bleating of the gazelle is longing for one's homeland; the howling of the wolf warns of theft; the cry of the fox is a warning of flight and moving away; and the yelping of the jackal is important matters, good and bad. Something similar to this will come under the letter Sad, God willing, in the entry on Sound.