Some animals that can produce a very soft sound even though they are very large animals the whale produces a load but very soft animal.
The rattle of a rattlesnake can sometimes sound like the roll of a snare drum.
Maybe whale or donkey.
lions
elephant
koalas
Bat.
None of the animal produce rustle sound.
Blue whale.
There are a lot of different animals that have a soft sound from a bird like animal an owl to other rodent animals that don't make much noise at all like a chipmunk.
Cuckoos are named after onomatopoeic sound which they produce: 'cuck-oo, cuck-oo'. Even thought the whole family is named by this unique sound, only one cuckoo species (Common cuckoo) is able to produce this sound. Other species communicate by producing different types of sounds. Characteristic 'cuck-oo, cuck-oo' sound is produced only by males. Females produce bubbling sound, which resembles the sound of the water that is running out of the tub after removing the plug.
Bat.
None of the animal produce rustle sound.
It is the noise that they produce -with whales, it is referred to as a song.
Blue whale.
Caterpillar, Turtle
If you want the largest sound made by an animal that animal is the Blue Whale.
According to my knowledge it is a whale it can produce 185 decibels of sound
SOFT
With most hard floors it will, but with things like carpets it won't at all.
The fizz sound is due to escaping carbon dioxide (CO2) gas which is dissolved in the soft drink. The CO2 dissolved in water forms carbonic acid (H2CO3).
One can produce a soft, high-pitched sound from a stretched rubber band by snapping it. It is easier to accomplish this if the band is stretched very tightly.
There are a lot of different animals that have a soft sound from a bird like animal an owl to other rodent animals that don't make much noise at all like a chipmunk.