the blood of a sacrificial fowl which was sprinkled on the doors and vessels
衈 centers on the ritual blood of a sacrificial bird, specifically the act of sprinkling it on doors and vessels as a ceremonial practice.
衈 combines 血 (blood) and 耳, which likely contributes the sound. The character is associated with ritual blood sprinkling, but the exact historical development is uncertain.
Blood 血 is sprinkled on doors and vessels, and the right side 耳 (ear) can be imagined as the vessel's handle or the door's latch that receives the ritual blood.
For ジ, imagine the ritual blood of a sacrificial bird being sprinkled on a door, and the sound of the sprinkling is a soft 'ji'—like the gentle hiss of liquid hitting a surface.