A feedback control system for data transmissions over a computer network, comprising: a natural language processor component executed by a data processing system comprising means to receive, via an interface of the data processing system, data packets comprising an input audio signal detected by a sensor of a client device; the natural language processor component comprising means to parse the input audio signal to identify a request and a trigger keyword corresponding to the request; a content selector component executed by the data processing system comprising means to receive the trigger keyword identified by the natural language processor and to select, based on the trigger keyword, a content item via a real-time content selection process; a feedback monitor component, of the data processing system, comprising means to receive data packets carrying auditory signals transmitted between the client device and a conversational application programming interface (112, 142) that established a communication session with the client device responsive to interaction with the content item; measure a characteristic of the communication session based in part on the auditory signals, the characteristic including at least one of signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and generate a quality signal based on the measured characteristic, the quality signal including one or more of a signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and the content selector component comprising means to adjust the real-time content selection process based on the quality signal. a natural language processor component executed by a data processing system comprising means to receive, via an interface of the data processing system, data packets comprising an input audio signal detected by a sensor of a client device; the natural language processor component comprising means to parse the input audio signal to identify a request and a trigger keyword corresponding to the request; a content selector component executed by the data processing system comprising means to receive the trigger keyword identified by the natural language processor and to select, based on the trigger keyword, a content item via a real-time content selection process; a feedback monitor component, of the data processing system, comprising means to receive data packets carrying auditory signals transmitted between the client device and a conversational application programming interface (112, 142) that established a communication session with the client device responsive to interaction with the content item; measure a characteristic of the communication session based in part on the auditory signals, the characteristic including at least one of signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and generate a quality signal based on the measured characteristic, the quality signal including one or more of a signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and receive data packets carrying auditory signals transmitted between the client device and a conversational application programming interface (112, 142) that established a communication session with the client device responsive to interaction with the content item; measure a characteristic of the communication session based in part on the auditory signals, the characteristic including at least one of signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and generate a quality signal based on the measured characteristic, the quality signal including one or more of a signal-to-noise ratio, ping time, choppiness, echo or number of dropped calls; and the content selector component comprising means to adjust the real-time content selection process based on the quality signal.