Waiting to hear back from vs Waiting on hearing back from

Some examples from the web:

• Well, Don's still waiting to hear back from Charlie.
• I'm waiting to hear back from Dana on that.
• I'm waiting to hear back from a friend.
• I'm waiting to hear back from a publisher.
• We are waiting to hear back from a Major.
• I've been waiting to hear back from Erin all weekend.
• Still waiting to hear back from the guy Who was working the front desk at the pawnshop that day.
• And he's still waiting to hear back from those desk jockeys.
• I checked with Director Manus, who's still waiting to hear back from the bank's corporate office.
• She's waiting to hear back from the D.A. About the charges.
• We're waiting to hear back from tox to see if he was taking his meds.
• He's been waiting to hear back from his doctor.
• I'm just waiting to hear back from a few more people, then you can approach her.
• Well, I'm still waiting to hear back from State on that.
• I'm still working on the seating chart and waiting to hear back from all your cousins on your mother's side.
• I am waiting to hear back from Senior's art forger.
• Plus I'm waiting to hear back from a friend who knows the phone game better than me.
• Just waiting to hear back from Michael's parents before doing the seating arrangements.
• She didn't show up for her last two classes, and I'm waiting to hear back from the hypnotherapist.
• And I'm waiting to hear back from garcia about tracking migrants Who may have traveled the same route as our unsub.

Some examples from the web:

• Waiting on hearing back from
• And then came one days on my hearing back.
• So I look forward to hearing back from you soon.
• I should be hearing back shortly.
• I'm just starting to get my hearing back.
• When I got my hearing back, there was this awful ringing.
• I'd request a little hearing back in your right ear.
• All right, folks, I like to call this hearing back to order.
• I need you to get that hearing back for me.
• I should be hearing back from UT any day now.
• She was at the school when we called Mason to look for her, but now we're not hearing back from either of them.
• I'm just waiting on you.
• Service is waiting on your vehicle.
• Just waiting on you, sweetcheeks.
• Still waiting on Joey's reassessment.
• I finally get my full hearing back, and the first thing I hear is that Wilson Fisk is out of prison.
• Mr. Corleone insists on hearing bad news immediately.
• But he can kill Bash in anger on hearing it.
• On hearing the sounds, they moved rapidly to the surface.
• On hearing of Ueda's death...
• On hearing of this, Odysseus died of grief.