1. A network device comprising: a memory; a processor executing instructions stored in the memory to perform an adaptive sounding process for a client in response to determining that all of the following conditions are jointly satisfied: (a) a wireless channel of the client measured using a channel correlation metric has changed by a first threshold amount, wherein the channel correlation metric is based on channel state information (CSI) measured at the network device; (b) a wireless throughput measured using a throughput gradient metric has decreased by a second threshold amount, wherein the throughput gradient metric is based on a difference between a current throughput measure and a prior throughput measure; and (c) the client's traffic measured using a traffic metric has exceeded a third threshold amount, wherein the traffic metric is based on a moving average of the client's frame size.