What tvengr says. Since you replaced the outlet you have likely eliminated possible arcing there. However, there could be arcing somewhere else.
You could switch off the breaker for that circuit, listen for interference. If it's still there you know it's in the wiring coming from a wiring fault or something else somewhere else, have to look further. If it's gone you know it's on that circuit. See what else is off. Now you know where to start looking. Unplug everything on that circuit, turn power back on. Now, listen for that interference. Some of these interference sources are very loud, sending RF all over the place, down the street. You may need to search all over the house, turn off circuits one at a time listening for the trouble. Begin plugging things back in. It's tedious but that's how you find it, a lot of trial and error. Nearly everything today has a switch mode power supply in it, battery chargers, radios, TVs, washing machines, furnaces, LED lamps, computers, coffee makers, ........... and poorly filtered ones (which are common) can create a great deal of radio noise. Occasionally it comes in from outside but most often it's in our own home.
