How is shabda-pramana free from four defects?

From Goutam Paul P
Sabda-praman is the aural reception of spiritual knowledge in disciplic succession. That is also processed through our senses. Then how Sabda-praman is free from the four defects?
There is scope for misunderstanding of the speaker, of the listener and there is scope for addition of noise in different written versions.

Answer Podcast:

https://www.youtube.com/watch?v=bJCt0pfOBLg