Audio synchronization and delay estimation

A method comprising:

• pre-processing an audio signal at a transmitter to generate a transmitter pre-processed audio signal comprising samples, each sample comprising a value and having a position in the transmitter pre-processed audio signal;
• reversing, by the transmitter, the positions of the samples of the transmitter pre-processed audio signal to generate a reversed audio signal;
• generating, by the transmitter, a transmitter discrete Fourier transform representation from the reversed audio signal;
• transmitting, by the transmitter, at least a section of the transmitter discrete Fourier transform representation to a receiver as audio metadata;
• receiving, by the receiver, the audio metadata comprising the at least a section of the transmitter discrete Fourier transform representation;
• pre-processing, by the receiver, a second audio signal;
• generating, by the receiver, a receiver discrete Fourier transform representation from the pre-processed second audio signal;
• generating, by the receiver, a correlation result in a discrete Fourier transform representation based on an element-wise multiplication of the at least a section of the transmitter discrete Fourier transform representation and the receiver discrete Fourier transform representation;
• performing, by the receiver, an inverse Fourier transform on the correlation result in a discrete Fourier transform representation to generate a correlated signal comprising one or more samples, each sample of the correlated signal having a position in the correlated signal and comprising a value;
• determining, by the receiver, a relative delay value based on the position in the correlated signal of a sample comprising a value with the greatest magnitude of the values of the samples of the correlated signal;
• and
• adjusting, by the receiver, playback of a third audio signal based on a current delay value adjusted based on the relative delay value.