System and techniques for sound-based call-quality detector are described herein. An audio sample can be received via a hardware interface from an on-going communication. The audio sample can be processed to produce a transcript. The transcript can be compared to a call-quality dataset to produce a call-quality degradation indication. Here, the call quality dataset includes indicia of communication quality. Network maintenance can then be performed in response to the call-quality degradation indication. The network maintenance can include adjusting a network device setting.