The goal of cochlear implants restores functional hearing by transmitting electrical pulses to auditory nerves and improves speech perception. Although current cochlear implant users showed greatly improved sentence recognition scores in a quiet environment, the issues of understanding speech in a noisy environment and listening to music are still challenging for them. Limitations of spectral and temporal resolution are thought to be related to these difficulties of cochlear implant users. As one of the approaches to resolve these challenging issues, benefits from the contralateral device of cochlear implant users were introduced. Two different types of binaural placements, bilateral and bimodal hearing, were continuously increased and they demonstrated some amounts of speech perception benefits. Bilateral hearing improves sound localization and speech perception in noise mostly due to the benefits from head shadow and redundancy effects. On the other hand, bimodal benefits are delivered by using acoustic low frequency information which is not represented in electric stimulation via cochlear implants. A review of the literature related to these topics was addressed.