You can now feed voice data to OpenSky -- our public feeding interface is finally live! Go to https://ui.atc.opensky-network.org/ to set up your receiver and also see your receiver's stats. In principle, you can use a similar setup to your traditional ADS-B receiver but you will generally need two different setups to feed both ADS-B and VHF at the same time.
Please note that this requires a separate user account for the moment, this will be remedied in the future when we will move the old accounts to the new system. Right now, you will also have to let us know through our contact form that you are planning to feed. This will also be consolidated soon.
Although in everyday life people prefer texting over calling, it is the opposite in aviation. Tactical information exchange between air traffic controllers (ATCOs) and pilots is still done over analog radio voice channels. For this purpose the VHF (Very High Frequency) band between 118MHz and 136MHz is used. The band is divided into 8.33kHz channels.
This site is interfacing Opensky Network's Air Traffic Communication (ATC Platform), which has been set up to collect voice recordings through a network of volunteers. The recordings are automatically transcribed and stored on our infrastructure. Of course there is also a handy API available!