19. The method of claim 9 , further comprising, based upon the analyzing the first audio signal, instructing, by the device, a user of the device to at least one of (i) move closer to the device, or (ii) reduce ambient sound in the vicinity of the device.
9. A method of characterizing an environment in which a device resides, the device comprising at least one speaker and at least one microphone, and the method comprising: producing a pilot tone by the at least one speaker; subsequent to producing the pilot tone, generating, by the at least one microphone, a first audio signal based on sound from the environment, wherein at least a portion of the sound comprises the pilot tone as reflected by one or more surfaces within the environment and the first audio signal includes one or more characteristics; analyzing the first audio signal to determine if the one or more characteristics of the first audio signal have been altered with respect to one or more characteristics of the pilot tone; generating a second audio signal by the at least one microphone; based at least in part upon the analyzing of the first audio signal, at least one of (i) selecting a signal processing model for performing speech recognition on the second audio signal, or (ii) altering a signal processing model for performing speech recognition on the second audio signal; and performing speech recognition on the second audio signal using the at least one of the selected or altered signal processing model.