What does it mean to have soft ears, what does it mean to recognize a daughter-in-law when she is on the kang, and recognize her shoes when she gets off the kang?

To have soft ears is to listen easily to whatever anyone says, and it means that a person has no independent opinion.

You can recognize your wife when you are on the kang, and you can recognize your shoes when you are on the kang.

This is from Guo Degang’s cross talk, which is a bit different from what you said. The original sentence is

You can know the women when you are on the kang. Getting to know the shoes after getting off the kang

It means

having a baby with your wife after getting on the kang

leave after getting off the kang.

In fact, it is using irony