ELT (emerg. locator transmitter) is being ignored?

I was on a flight from Dulles to Miami recently. I was doing a check ride for another colleague. I was listening to the ATC exchanges on the audio Channel 9. About 14:20H EST we reported a weak ELT signal to the controller. The controller, quite busy didn't acknowledge the transmission, nor was it mentioned in later transmissions. I found myself wondering what's going on and why the ELT is being ignored? anybody can enlighten me? thanks.