The next line of "the sound of firecrackers is the end of the old year" is "the drums and gongs are in full swing to welcome the new year".

"The sound of firecrackers is the sound of the old year" is from "New Year's Day" by Wang Anshi of the Song Dynasty.

Originally:

The sound of firecrackers marks the end of a new year, and the spring breeze sends warmth into the tassel.

A thousand doors and tens of thousands of tels, always changing the new peach for the old one.

Interpretation:

At the sound of the firecrackers, the old year is over; the warm spring breeze brings in the New Year, and people joyfully drink the newly brewed Tusu wine. The rising sun shines on thousands of families, who are busy removing the old peach talismans and replacing them with new ones.

Appreciation

This poem describes the scene of the Spring Festival when the old is removed and the new is welcomed. The sound of firecrackers sends away the old year, and the breath of spring is felt when drinking the mellow Tusu wine. The rising sun shines on thousands of families, and the peach symbols on their doors are all replaced with new ones.

This is a piece of writing to welcome the New Year in ancient times. It is based on folk customs, sensitively taking the typical materials of the common people during the Spring Festival, seizing the representative details of life: lighting firecrackers, drinking tusu wine, and replacing the new peach symbols, which fully expresses the joyful atmosphere of the New Year's festival and is rich in the atmosphere of life.

Refer to Baidu Encyclopedia - New Year's Day for the above