def hz2fft(fb, fs, nfft):
    """
    Convert Bark frequencies to fft bins.

    Args:
        fb (np.array):  frequencies in Bark [Bark].
        fs (int):       sample rate/ sampling frequency of the signal.
        nfft (int):     the FFT size.
    Returns:
        (np.array) : fft bin numbers.
    """
    return (nfft + 1) * fb / fs