The introduction of Siri back in 2011 has been the trigger for a massive growth in the use of voice control on the smart devices we interact with. Alexa and Google Assistant have followed hot on Siri’s heels, and today it is possible to talk to your television, your car and a host of other devices -  even ones you don’t need to. However, you may not be aware that the use of voice as a man-machine interface has been common in the ...