nostr:nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpqcu4r6pt94plck34vtw9t3zj974k0vl0z8x9gew5vdp2ukw3ekr4qwrk3ke to be clear, the shopping cart is not using audio, they're using an electric signal that's in the audio range in terms of frequency, so an electric speaker playing at that frequency will...