1. A method comprising: at a device comprising one or more processors and a memory storing one or more programs for execution by the one or more processors: sending a plurality of test audio packets at a level of signal complexity deviating from a model level of signal complexity to a destination device through one or more networks; receiving a response to the plurality of test audio packets, wherein the response is indicative of a value for a quality of service characteristic associated with the one or more networks, wherein the value for the quality of service characteristic is determined by how the plurality of test audio packets deviate from the model level of signal complexity when received by a remote device; and responsive to receiving the response to the plurality of test audio packets, activating a signal correction action when the value for the quality of service characteristic fails to meet a performance threshold.