Today, I'm creating the automatic farm with Dispenser. After that, I go far away from the automatic farm, but I can hear Dispenser sounds when the sound source is very far away from player. Example is in the video! - the Dispenser sounds are from automatic farm.
Video:
https://youtu.be/nMcXzLyQJWQ
Environment
Java Version: 1.8.0_51 - 64 bit
OS System: Windows 10 - 64 bit
RAM: 8 GB
GPU: Geforce GTX 1060 (3GB)
Same here. I can be 20-30 blocks away, and it sounds like the dispenser is right next to me.