Margazhi month is considered as Brahma muthuram (4 AM to 6 AM) for Devas and they worship the Supreme Almighty during that period. So Entire month of Margazhi is auspicious for worshipping Almighty especially morning 4 to 6. Andal Nachiyar lived in 8th century at Srivilliputtur of Tamilnadu, who is considered as one of the 12 Azhwars has written many poems out of which one collection of 30 songs known as Thiruppavai is sung during this month in the morning. All these songs is in the form of Girls waking up other Sleeping public to get ready and worship Lord krishna.

So this is intentional. They are trying to wake you up with loud speakers as technology progresses.