Shulker Sounds... In the mountains

Minecraft developers,

In a survival world recently, I made a house on a mountain, but for some reason, I heard a sound that went something like "blwech!", and I thought it was a zombie. I thought it was strange because there were no caves, and it was daytime. Later, I remembered it was a shulker noise. This was not an online world, and it was never changed to creative. I would like it if you could fix this.

From, C.W.