def METHOD_NAME(self, sig, bak, ovr, is_personalized_MOS):
    if is_personalized_MOS:
        p_ovr = np.poly1d([-0.00533021, 0.005101, 1.18058466, -0.11236046])
        p_sig = np.poly1d([-0.01019296, 0.02751166, 1.19576786, -0.24348726])
        p_bak = np.poly1d([-0.04976499, 0.44276479, -0.1644611, 0.96883132])
    else:
        p_ovr = np.poly1d([-0.06766283, 1.11546468, 0.04602535])
        p_sig = np.poly1d([-0.08397278, 1.22083953, 0.0052439])
        p_bak = np.poly1d([-0.13166888, 1.60915514, -0.39604546])
    sig_poly = p_sig(sig)
    bak_poly = p_bak(bak)
    ovr_poly = p_ovr(ovr)
    return sig_poly, bak_poly, ovr_poly