def METHOD_NAME(spectrogram):
    """Calculate normalized power sequence from spectrogram
    Parameters
    ----------
    spectrogram : array, shape (T, `fftlen / 2 + 1`)
        Array of spectrum envelope
    Return
    ------
    npow : array, shape (`T`, `1`)
        Normalized power sequence
    """
    # frame based processing
    npow = np.apply_along_axis(_spvec2pow, 1, spectrogram)
    meanpow = np.mean(npow)
    npow = 10.0 * np.log10(npow / meanpow)
    return npow