The transistor was first demonstrated by Walter H. Brattain and John Bardeen to their higher-ups at Bell Laboratories. A microphone and headphones were connected to the transistor, and the device was actually spoken over "with no noticeable change in quality" as Brattain wrote in his notes about that day. The name transistor came from its electrical property known as trans-resistance. The original device, which the researchers first had working on 16 Dec 1947 was a point-contact version, which was later improved by William Schockley as a junction transistor. The inventors shared the 1956 Nobel prize in physics for their work. The transistor replaced the bulkier vacuum tube, and was referred to as the electronic engineer's dream.

Greece 1947 USA Transistor Radio December 23rd, 1947 : Bell Labs demonstrates the worlds first Transistor Radio, Bell had also created the first transistor just a few months earlier. Many companies have claimed and are attribeted as the worlds first including Texas Instruments, Sony and the German firm Intermetall but it depends on how you view the quality of the radios , so I will leave that to others to judge.