A conferencing endpoint comprising: a processor (206, 208, 210) for executing programs to perform conferencing endpoint operations; memory coupled to the processor (206, 208, 210) for holding programs executed by the processor (206, 208, 210); a first Ethernet controller coupled to the processor (206, 208, 210) and for coupling to at least one Ethernet-connected microphone (114 A), the first Ethernet controller including precision time protocol, PTP, capabilities and providing first audio samples from the at least one Ethernet-connected microphone; an audio input module coupled to the processor (206, 208, 210) and for coupling to a locally connected audio source and for receiving second audio samples from the locally connected audio source; a pulse generator connected to the audio input module and the first Ethernet controller, the pulse generator being configured to cause the first Ethernet controller to capture a first PTP timestamp and to cause the audio input module to receive an audio sample of the second audio samples, the audio sample being flagged by the pulse generator at the time of capturing the first PTP timestamp; and flash memory storing programs executed by the processor (206, 208, 210) to perform acoustic echo cancellation operations, to obtain the first PTP timestamp, to correlate the audio sample to a first Ethernet controller audio sample at the first PTP timestamp, to correlate the second audio samples of the locally connected audio source and the first audio samples of the at least one Ethernet-connected microphone based on correlating the audio sample to the first Ethernet controller audio sample at the first PTP timestamp and to use the correlation in acoustic echo cancellation operations. a processor (206, 208, 210) for executing programs to perform conferencing endpoint operations; memory coupled to the processor (206, 208, 210) for holding programs executed by the processor (206, 208, 210); a first Ethernet controller coupled to the processor (206, 208, 210) and for coupling to at least one Ethernet-connected microphone (114 A), the first Ethernet controller including precision time protocol, PTP, capabilities and providing first audio samples from the at least one Ethernet-connected microphone; an audio input module coupled to the processor (206, 208, 210) and for coupling to a locally connected audio source and for receiving second audio samples from the locally connected audio source; a pulse generator connected to the audio input module and the first Ethernet controller, the pulse generator being configured to cause the first Ethernet controller to capture a first PTP timestamp and to cause the audio input module to receive an audio sample of the second audio samples, the audio sample being flagged by the pulse generator at the time of capturing the first PTP timestamp; and flash memory storing programs executed by the processor (206, 208, 210) to perform acoustic echo cancellation operations, to obtain the first PTP timestamp, to correlate the audio sample to a first Ethernet controller audio sample at the first PTP timestamp, to correlate the second audio samples of the locally connected audio source and the first audio samples of the at least one Ethernet-connected microphone based on correlating the audio sample to the first Ethernet controller audio sample at the first PTP timestamp and to use the correlation in acoustic echo cancellation operations.