Is sound louder at night than it does during the day?

Things are louder at night because the upper atmosphere i.e. stratosphere etc moves closer to the earth and so your sounds waves travel less distance and travel further than they would in the day, plus in the night there is less external noise so again a single noise will seem louder because it stands out. Hope this helps.

because the sound absorbing substances like mans,vechilesetc are absent in night.