yes it is
The fibres in a sponge move and trap/absorbthe sound instead of letting the sound travel to another place, that is a very simplified version.
No. Although spelled similarly and having a silent E, they have different vowel sounds. The O in sponge (spunj) has a short U sound as in spun. The O in smoke has a long O sound as in poke or soak.
No. There is really no one material that is sound proof. Many materials can reduce sound levels, but reducing sound is not what you might think of when you hear sound proof.
the material that was used.
A sound proof wall.
The cast of Sound Proof with Leah Rose - 2008 includes: Maino
Quietrock.
No. The word proof has a long OO (long U) sound as in roof.The long O (oh) is seen in the word profess.
Yes, it would hurt. At the speed of sound, the impact from a sponge hitting you would be powerful enough to cause significant damage, possibly leading to injury or even death.
Use sound-proof drywall.
In a sound proof room
Yes. Echolocation works by bouncing waves off of objects. A sound proof room would not allow sound to escape but there are still walls in the room to allow a bat's echolocation to bounce off of and back to the bat.