Contralateral routing of signal (CROS) amplification systems are intended to be used when (essentially) one ear is normal or has a mild/moderate hearing loss (i.e., is generally a candidate for amplification) and the other ear is (more-or-less) not “aidable.” CROS hearing aids might be recommended for single-sided deafness (SSD) or for people with very poor unilateral word recognition scores.