Just tapping on the console does not simulate knocking. As dannobee said, there are also many other noises which do affect the overall reading of a knocking sensor.
You can do the following cheap set up:
1. Simply connect the two wires to the knock sensor and lead them to the cars interior, here connect these wires to a cheap LM 368 amplifier where you can connect common in ear phones. Those tiny amps can simply be fed by a 9v battery.
https://www.ebay.de/itm/255283194260
And then you can enjoy how your engine really sounds, its nice and beside knock detection "by ears" its also a very good tool to hear if anything else in the engine could sound odd. Then you can connect that sensor to your ECU of your EFI system.
I installed my sensor at the middle of the top of the crankcase behind the alternator, see pic above. And btw for me personally its the most secure check for detonation at lower and higher rpms, as I can hear it --> by myself.