What sound is heard from an audio device experiencing RF interference from a CW transmitter?
Why Audio gear doesn't have a receiver's BFO, so it can't turn a CW carrier into a musical tone. What happens is that a nonlinear junction in the audio circuit rectifies the strong RF, and the recovered DC follows the keying envelope of the transmission. The result is a buzz, hum or click that switches on and off in step with the dits and dahs.
Watch out The choice describing a pure audio tone assumes the audio device beats the signal against a local oscillator the way a ham receiver does, which it cannot. Severely distorted or garbled audio is the classic symptom of SSB phone interference, not CW.
No BFO in a stereo: CW comes through as clicks and hum that follow the key, SSB comes through as garbled speech.