Echo latency estimation

A computer-implemented method, the method comprising:

• sending reference audio data to a loudspeaker to generate output audio, the reference audio data including a first reference sample and a second reference sample;
• capturing microphone audio data using a microphone, the microphone audio data including a first representation of at least a portion of the output audio;
• calculating a first value of a threshold, the first value corresponding to a 99th percentile of the reference audio data during a first time period;
• determining a first magnitude value corresponding to the first reference sample;
• determining that the first magnitude value is below the first value, indicating that the first reference sample is below the 99th percentile;
• calculating a second value of the threshold that is lower than the first value, the second value indicating the 99th percentile of the reference audio data during a second time period;
• determining a second magnitude value corresponding to the second reference sample;
• determining that the second magnitude value exceeds the second value, indicating that the second reference sample is at or above the 99th percentile;
• generating subsampled reference audio data including the second reference sample and corresponding to portions of the reference audio data at or above the 99th percentile;
• determining cross-correlation data corresponding to a cross-correlation between the subsampled reference audio data and the microphone audio data;
• determining a first peak value in the cross-correlation data, the first peak value indicating a beginning of the first representation;
• determining, using the first peak value, an echo delay estimate value corresponding to a delay between sending the reference audio data to the loudspeaker and the microphone capturing the first representation in the microphone audio data;
• determining second reference audio data using the reference audio data and the echo delay estimate value, the second reference audio data synchronized with the microphone audio data;
• and
• subtracting the second reference audio data from the microphone audio data to generate output audio data.