My simple and short preference is for "sounds" (note definition 5).

The sounds of the city outside could be heard through the paper-thin walls.

or

Walking through the forest, one can experience the sounds of nature.

My simple and short preference is for "sounds" (note definition 5).

The sounds of the city outside could be heard through the paper-thin walls.

or

Walking through the forest, one can experience the sounds of nature.

There are also more famous examples: Sounds of Silence, Sounds of Then. Googling "sounds of" or "sounds from" will bring many many examples which may fit your desired use.