Embodiments of an access point (AP), station (STA) and method of sounding are generally described herein. The AP may transmit, during a transmission opportunity (TXOP), a trigger frame (TF) to indicate that an STA is to transmit an uplink sounding packet during an uplink sounding period of the TXOP. The AP may attempt to detect the uplink sounding packet during the uplink sounding period. If the uplink sounding packet is not detected during the uplink sounding period, the AP may transmit a recovery packet to cause other STAs to determine a busy condition during the uplink sounding period. If the uplink sounding packet is detected during the uplink sounding period, the AP may determine a channel estimate for the STA based at least partly on the uplink sounding packet.