ISDN line: This is a type of phone line that delivers very high-quality audio to the broadcasters. ISDN is used widely across the radio industry with all the main players, including the BBC, Wireless Group, Bauer and Global all using it for live guests who can’t get to the studio.
ISDN is a digital line, compared to a normal analogue phone line. This means higher-quality sound can travel down the line via use of a piece of kit called a Codec.
ISDN lines can run various different Codecs. Codecs are basically a software that compresses a digital stream and sends it in a smaller file size. This allows for a fast transfer of a file (a phone call) and fast unpacking of it to its original quality. Codecs most often used in ISDN calls are G722 and APTX.
Both are used widely across the radio industry. At Shout! Communications we have equipment that can use both, so it doesn’t matter what Codec the radio studio use we can still get through to them. In our studio and during radio days we use a Codec unit that has both ISDN capabilities and ‘normal’ phone call capabilities.
Another key part of our studio operations, especially during radio days, is the capacity to record interviews. We use a programme called Pro Tools, which can isolate tracks to enable us to record ‘clean’ feeds. The programme also records a ‘stereo mix’; this is when it combines the clean feeds of the phone line and also our microphones, typically what you would hear if you were listening to the radio.
Our studio is also perfectly suited to recording podcasts and we do this often. We have a producer mic on the outside of the booth so we can feedback to the presenter/ spokesperson during and after takes.