While not canonical proof, there is further evidence that Ferengis literally undergo some sort of dramatic physical change in their ears during puberty (may or may not be complete replacement of ears), as implied by Ferengi using the term "lobeling" to refer to a young Ferengi.
In the DS9 episode "Profit and Lace"
ISHKA: You're overreacting.
QUARK: Whatever you say.
ISHKA: Reminds me of when you were a lobeling. You were always such a miserable child.
QUARK: Moogie, leave me alone.