I think I know exactly what's going on here.
Our inner ears can heal. This has been proven experimentally. A small handful of humans, including myself have experienced this using new medical interventions. There are switches to tell our haircells to regrow, which in turn causes the hearing cells to signal the nerves and the nerves regrow and make new connections. The switches in our inner ear stem cells aren't only activated by lab chemicals like ly411575, but also with proteins called growth factors that are already present in our body, in our blood, in platelets. There is a barrier, much like the blood brain barrier, called the blood labyrinth barrier, that separates the inner ear fluids from our systemic blood flow. There is no blood in the inner ear, it is a clear fluid called endolymph. I think that the blood labyrinth barrier is blocking the platelets from reaching the inner ear and activating the stem cells. Either the size of platelets in birds and other vertebrates are smaller and can pass through the blood labyrinth barrier or their barriers are more permeable, thus allowing the platelets to pass.
This barrier is needed however to protect our inner ears from toxicity and drugs that are causing ototoxicity are made of molecules that are small enough to pass through the barrier.
There is a substance called manitol that increases the permeability of the barrier, but there is another path to the inner ear called the round window membrane and the oval window membrane. The oval window is mostly blocked by the stapes bone. The growth factors are small enough to pass through the round window membrane, which is exactly how the drug fx-322 is administered.
I'm pretty damn sure that's the answer. These researchers can't see the forest for the trees and the government needs to let us have injections of PRP.
Oh wait, PRP is not regulated. Any ENT or otolaryngologist with a medical license and the know-how to do intratympanic injections can do this today if they want. They just need PRP kits and a centrifuge.