def downgrade_sample_rate_of_labels(labels, original_sample_rate, needed_sample_rate):
    """This function downgrades sample rate of provided labels to needed_sample_rate
       It is worked through calculating ratio between original_sample_rate and needed_sample_rate
       and then thinning provided labels

    :param labels: ndarray, (n_labels,)
    :param original_sample_rate: int
    :param needed_sample_rate: int
    :return: ndarray, thinned labels with new downgraded sample_rate
    """
    ratio=int(original_sample_rate/needed_sample_rate)
    new_labels=labels[::ratio]
    return new_labels