The fourth commandment speaks of more than just the priests directly and more to the point anything magical.

4. It is forbidden to beseech or manipulate any form of magic other than that expressly mentioned above. To do so is to mock the gods and a blasphemy of your combat prowess.

So, as I see it, unless the echo is some form of inspiration *non-divine* and it passes spellbane, then and only then would it not fall into the "any form of magic". I haven't played in many months so I forget the echos.