Influence of the Electrical Dynamic Range (EDR) on Speech Perception, Vocabulary, and Quality of Life in Young Children

A person’s electrical dynamic range (EDR) in a cochlear implant (CI) is defined as the difference between the highest tolerable current level, without discomfort or pain (typically called a C-level), and their perceptual threshold for sound (typically called a T-level) (Park et al., 2023).

In a prospective longitudinal study involving 102 children, Ching and colleagues (2025) examined the impact of the measured EDR at age three on speech perception in quiet and noise, receptive and expressive vocabulary, and health-related quality of life (HRQOL) at age nine. Correlation and regression analyses were utilized to determine the effect of EDR, as measured at three years of age, on the children’s performance at nine years of age (speech perception, vocabulary, HRQOL).

Results revealed that wider EDRs at three years were associated with higher HRQOL at age nine. Children with wider EDRs likely had better early auditory access, resulting in improved communication abilities. Improved communication has been shown to predict HRQOL (Ching et al., 2021). This was a novel finding and supports the importance of optimal stimulation levels at a very young age.

Not unexpectedly, an earlier age at CI activation was associated with better speech perception in quiet and noise, as well as improved receptive and expressive vocabulary. After controlling for the effects of age at activation, EDR at age three did not affect speech perception or vocabulary.

The authors also found that EDRs remain stable from three-nine years. Previous recommendations were to provide programming throughout a recipient’s lifetime; however, the authors conclude that, with the current generation of CI recipients, once Ts and Cs are optimal, there may be no need to reprogram.

References

Ching, T. Y. C., Hou, S., & Incerti, P. (2025). The influence of electrical dynamic range in cochlear implants of children at age 3 years on speech perception, vocabulary and quality-of-life outcomes at age 9 years. International Journal of Audiology, 1–9. Online ahead of print.

Park, B., Thak, P. K., Park, E., Choi, S. J., Lee, J., Kwak, S., Jung, H. H., Im, G. J. (2023). Dynamic range and neural response threshold in cochlear implant mapping can be useful in predicting prognosis related to postoperative speech perception. Journal of Audiology & Otology, 27(4), 212-218. doi: 10.7874/jao.2023.00374.