ESP-TEL is a single-chip, audio tele-conferencing solution based on Espressif’s ESP32-LyraT-Mini development board. No additional digital-signal processing (DSP) chip is needed. Only one ESP32 is used for the front-end speech recognition. This solution can simultaneously realize the functions of audio-conference calling, voice interaction and human-machine interface (HMI).

ESP-TEL Resources
1. ESP32-LyraT-Mini Getting-Started Guide: https://docs.espressif.com/projects/esp-adf/en/latest/get-started/get-started-esp32-lyrat-mini.html
2. ESP VoIP is a telephone client based on the standard SIP protocol: https://github.com/espressif/esp-adf/tree/master/examples/advanced_examples/voip
3. Espressif's Audio DevKits: https://www.espressif.com/en/products/devkits/esp-audio-devkits
4. Espressif's Audio Development Framework: https://github.com/espressif/esp-adf
5. Espressif's esp_sr provides basic algorithms for speech-recognition applications: https://github.com/espressif/esp-sr
6. ESP Technical Documents: https://ww…