MAtmos Minecraft Atmosphere, Ambient Sound Effects Minecraft Mod
One of the noticeable shortcomings in Minecraft is actually one of the bonus points of one of its clone style competitors, Mythruna (if you want something Minecraft-y and free to play, I'd highly recommend checking it out via the link I so subtly just left for you) and that is ambient sound.
When one plays Minecraft, one rather feels that one is being followed by a talented but somewhat unhinged pianist who has his piano on some rather heavy duty trundlers. Aside from zombie groans, skeleton rattles, chickens clucking and the occasional downpour, Minecraft isn't exactly heavy on the old ambient sound. If you turn the music off the world quickly becomes aurally bland.
MAtmos fixes that particular issue by adding atmospheric sound to the game. When you walk on a sandy beach, you'll hear the water lapping gently against the blocky shore. When you climb a snowy mountain, you'll hear the cold wind whipping past you. Whilst traipsing through a forest, you'll have birds serenading you with song, and when you're about to tumble into a lava pit, you'll hear the rumble of molten rock. As usual, I downloaded the mod and installed it myself and I can report that I was entirely delighted with the way it performed. The moment I spawned on my beach I heard frogs croaking (or perhaps its crickets chirping, I never was much of a biologist) and waves washing up against the shore. It looked perhaps a little odd to have the water static whilst the wave sound played, but you can't have everything.
Because the mod constantly takes notice of your surroundings, you won't find yourself in the strange position of hearing rain deep inside caves. In fact, if you're up on one of the aforementioned windy hills and you secrete yourself inside a little cave and wall yourself in, the wind noise will stop, even though the gale is undeniably still howling outside. There's a little teensy bit of lag, but not much.
MAtmos works by scanning the blocks around you, taking into account sunlight and weather conditions, then working out what kind of environment you're in. When it's made the assessment, it plays the appropriate sound for that sort of area. All the data for various environments is stored in an editable database, so you can even create your own atmospheres if you don't mind getting your hands a little code-y.
A quick examination of the sound files reveals all sorts of potential atmospheres, with sounds for water, wildlife, wind, weather, caves and even citadels, yes, citadels.