def sound_match(sound, features):
    """
    Match a sound by a subset of features.

    .. note::

        The major idea of this function is to allow for the convenient matching of
        some sounds by defining them in terms of a part of their features alone.
        E.g., [m] and its variants can be defined as ["bilabial", "nasal"], since
        we do not care about the rest of the features.
    """
    for feature in features:
        if not set(feature).difference(sound.featureset):
            return True
    return False