In Real world.
Sound is a form of energy which is created in multiple ways some of the basic ones being collision and through verbal cortex, sound in general requires a medium to travel i.e air, water and earth. Sound in general travels at a very fast pace but it travels the fastest through earth as the inter atomic distance between the nucleus is the least, Sound travels in form of waves and has different effects at different frequencies, A high frequency sound can be used to break glass and causes a severe headache whereas a low frequency sound in not even perceived by human ears and thus in real life is used to tame animals. Sound can even travel through large distances via amplification and other useful techniques.
In Naruto-verse.
Sound is an element which originates from otagakure and requires the mastery over wind and lightning. Just like in real life sound in naruto-verse also travels at tremendous speed and this very aspect make this element hard to deal with and with crafty use it can be put to great application, Sound can be put to great application as it has various usage in naruto verse via usage of chakra.
1. Raw Destruction- Sound can be used for direct attacks, these sound waves are high energy waves and can obliterate almost everything in their path if the carry the required amount of energy
2. Physical imbalance- I am not much sure about this part but this in my opinion basically works by distorting the way the brain works using sound waves, this in turn results in peculiar and hindered movements.
3. Genjutsu- Sound can be used a medium to cast genjutsu on th opponent, these genjutsu can be triggered by any sound and thus being creative with it is essential as genjutsu in itself is all about stealth, they are hard to avoid due to being fast and are also hard to deduce.