The term 'Sound Transmission Part' can be summarized as an AUDIO device, which is a five-letter word. This device is used to transmit sound from one place to another. It is commonly used in the entertainment industry, such as for concerts and music festivals, as well as in the broadcasting industry. It is also used in many other applications, such as for teleconferencing and video conferencing. The AUDIO device is an important part of sound transmission, as it helps to ensure that sound is transmitted accurately and efficiently.