Device arbitration for digital assistant-based intercom systems

Systems and processes for operating an intercom system via a digital assistant are provided. The intercom system is trigger-free, in that users communicate, in real-time, via devices without employing a trigger to speak. Acoustic fingerprints are employed to associate users with devices. Acoustic fingerprints include vector embeddings of speech input in an acoustic-feature vector space. Speech heard at multiple devices, as embedded in a fingerprint, may be clustered in the vector space, and the structure of the clusters is employed to associate users and devices. Based on the fingerprints, a device is mapped to a user, and the user employs that device to participate in a conversation, via the intercom service.