Radio Frequency is band-dependent, it's the range from 20 kHz to 300 GHz. A human ear can't even hear noise in the radio-frequency band. The majority of the noise we hear from the electromagnetic pickups in an instrument is EMI. Yes, there's a RF component, say for instance Wi-Fi, but that's not ALL of it. EMI encompasses all that noise, not just RFI. Electromagnetic interference - Wikipedia "Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum" EMI comes off of things like neon lights, the compressor from an air conditioner (or refrigerator), or even power lines.