import typing


def voiceless_variants(base_phone) -> typing.Set[str]:
    """
    Generate variants of voiceless IPA phones

    Parameters
    ----------
    base_phone: str
        Voiceless IPA phone

    Returns
    -------
    set[str]
        Set of base_phone plus variants
    """
    return {base_phone + d for d in ["", "ʱ", "ʼ", "ʰ", "ʲ", "ʷ", "ˠ", "ˀ", "̚", "͈"]}