Q: What is the advantage of bilateral cochlear implantation over monaural implantation in patients with severe bilateral sensorineural hearing loss? A: (1) Speech recognition in quiet and noisy environments is significantly better with bilateral than unilateral implants (2) Sound localization is 18.5% better with bilateral implants, especially in noisy environments where speech recognition is 20% better on average (from the literature) (3) Bilateral implants can be done in separate sessions or at the same time, with no significant difference in surgical risk for the latter compared to unilateral implants, and the surgical time is unilateral implantation, and 1.5 times longer than unilateral implantation. Therefore, simultaneous implantation is more cost effective. Because bilateral cochlear implantation is significantly better than unilateral implantation, bilateral implantation has become a trend overseas. The main reason why bilateral implants are not yet widely available in China is probably the cost to the patient.