Schafer et al (2011) investigated bimodal and bilateral cochlear implant arrangements across three binaural factors (binaural summation, head shadow, and binaural squelch) with regard to speech recognition in noise. The authors binaural squelch analysis was based on 31 experiments and 374 subjects, binaural summation analysis was based on 34 experiments and 375 subjects and binaural head shadow analysis was based on 30 experiments and 339 subjects.
In general, the average cochlear implant (CI) listener performs significantly better with bilateral CIs (as compared to monaural implantation) with regard to the three binaural factors investigated (binaural summation, head shadow, and binaural squelch). The average bimodal listener perceives advantages with regard to two of the three binaural factors (binaural summation and head shadow) when compared to the average monaural CI listener. However, in general, when comparing bilateral and bimodal CI arrangements, similar results were determined across binaural listening arrangements.
For More Information, References and Recommendations
Budenz CL, Roland JT, Babb J, Baxter P, Waltzman SB. (2009) Effect of Cochlear Implant Technology in Sequentially Bilaterally Implanted Adults. Otology & Neurotology (30)6:731-735
Eapen, RJ, Buss, E, Adunka, MC, Pillsbury, HC and Buchman, CA. (2009): Hearing in Noise Benefits After Bilateral Simultaneous Cochlear Implantation Continue to Improve Four Years After Implantation. Otology & Neurotology 30(2):153-159.
Sammeth CA, Bundy AM, Miller DA. (2011) Bimodal Hearing or Bilateral Cochlear Implants—A Review of The Research Literature Seminars in Hearing 32(1):3-31.
Schafer EC, Amlani AM, Seibold, Shattuck (2007) A Meta-Analytic Comparison of Binaural Benefits between Bilateral Cochlear Implants and Bimodal Stimulation. Journal of the American Academy of Audiology 18:760–776.
Schafer EC, Amlani AM, Paiva D, Nozari L, Verret S. (2011) A Meta-Analysis to Compare Speech Recognition in Noise With Bilateral Cochlear Implants and Bimodal Stimulation. International Journal of Audiology 50:871-880.