Would love to see how this works vs. just finding the max correlation of the 1d sampled stream vs the base data. If that's no good - try fft on the 1d sample and rescale.
The FFT on the 1D audio would not work because the FFT of a sub sample would not be immediately recognizable in the FFT of the whole. This is why I took the spectrogram approach, which is many FFTs over time.