Today’s invention is shoes -with sound effects.
The shoes would have ultra-soft, crepe soles, but they would also contain a pair of speakers wired to an mp3 player.
The wearer could choose a sound effect (using a wireless controller) and then, as each foot touches the ground, the chosen sound plays -as a footstep.
Aside from potential pythonesque humour (coconut shells) this could enable a user to appear more assertive by playing a loud, crunching step.
The footsteps’ volume could also be turned up by way of announcing someone’s arrival or warning pedestrians that the shoe wearer was running down a busy street behind them.