There are many reasons as to why this may occur.
The cable connecting the headphones to the device may have a short in it.
The drivers (the speakers) may have blown out (however, this is quite unlikely). The headphone jack may be malfunctioning.
The device may not be playing anything.
Since Sennheiser manufactures its own earphones, it stands to reason that they would recommend their own earphones. Their site Sennheiser will have plenty of suggestions.
Hearing problems from a Sound Grenade are TEMPORARY; however if someone were to be REPEATEDLY exposed to Sound Grenades (many times), they would MOST LIKELY have PERMANENT HEARING PROBLEMS.
They were receiving instructions and timings. Also, because sound travels much slower than light, each performer would have had the music directly in their earphones to ensure they all stayed in time.
The opposite of hearing sound would be making sound. The word speaking is more closely the opposite of listening.
I'm sure anyone would be worried about hearing voices. It means you are not mentally sound.
So that they can fit into your ears. What would you prefer round or square earphones?
Not into the PlayStation 3 itself, but pretty much all TVs or sound systems would provide a jack for earphones to be plugged in.
Depends on if you mean hearing in a space shuttle, or hearing out in real "space." Sound travels through air, so if you were out in real "space," sound waves would not travel since there is no air (or other medium for sound to travel in). If you were in a space shuttle, with air, and different objects, sound would be transmitted much in the same way that it is on Earth, and would be perceived much in the same way as well. This is why astronauts can speak freely with one another aboard space crafts.
Armadillos have excellent hearing and the distance would depend upon the frequency of the sound.
No. There is no reason that it would.
transduct, amplify, transmit, integrate
That would be the hearing sensitivity of the person trying to hear the sound.