1. A computer-implemented method for selecting a response to an audio stream query, the method comprising: receiving, over a network, a self-support query including spoken content from a user recorded by a remote mobile device; determining a set of paralinguistic features from the spoken content; estimating an emotional state of the user based on the set of paralinguistic features; identifying text strings representing subject matter based on the spoken content in the audio stream query; determining two or more query responses corresponding to the text strings representing the subject matter; selecting, from a query response database, one of the query responses to present to the user based, at least in part, on the emotional state of the user and an uplift model used to select query responses for users with the emotional state; receiving, over the network from the remote mobile device, a user reaction to the query response; determining a favorability metric associated with the user reaction; updating the uplift model based on the attribute of the user, the user reaction and the favorability metric; and based on updating the uplift model, transmitting an additional query response to the remote mobile device, wherein the additional query response is selected based on the uplift model for users with the emotional state of the user.