The cow is sacred in India. India reveres the cow, India celebrates the cow. India may prove its reverence for the cow by celebrating a noiseless Diwali.
Science tells us that cows are prey animals, simply put, they are alert and sensitive to loud noises and sudden movements.
While every pet parent and welfare agency in the country is educating people on the dangers of noisy firecrackers for cats and dogs, let us not forget other animal populations.

Livestock Facts
India is home to over 500 million head of livestock. These include Cattle, Buffalo, Sheep, Goat, pig, Horses & Ponies, Mules, Donkeys, Camels, Mithun and Yak.
Cows and other city dwelling animals unfortunately have no opportunity to display these natural behaviours. Added to their confinement, during Diwali is the stress of noise and loud noises.
The flight zone is the distance within which a person can approach an animal before it moves away. Herd animals usually turn and face a potential threat when it is outside of their flight zone, but when it enters the flight zone, the animal turns and moves away.
Temple Grandin, Mark J. Deesing, in Genetics and the Behavior of Domestic Animals (Second Edition), 2014
So, for cows sake, make it a quiet Diwali.