Transfers digital data into a format that the tele-lines can handle, digital sounds: 1 = high pitch 0 = low pitch.
The data is perceived as a kind of whistle.
Images are well-known to have a lot more data in them than text, take longer to load. But the tele-lines aren't really designed to handle imagery, it is biased to text, which is easier to represent with 1s and 0s.
This is the basis of my "communication with images only, no language" that the idiot JeesumCrowe couldn't comprehend.
If one image has a lot more data in it than text (thousand words, anyone?), then beings that are able to communicate without langauge, with images only, could reach a much higher connection with each others than humans bound by language can. A robot that can print what it saw to another robot that can interpret the image. Almost like a collective mind, with data-lines designed for imagery.
The bandwidth of the tele-line decides the amount of data that can fit into it. Fibre optics has great width. Silicon Chip has more about the fibre optics. Data travels as ligh pulses, not whistle. Light is faster, wider, more reliable.