Background: In unilateral cochlear implant (CI) users, hearing aid (HA) usage in the non-implanted ear is important to provide additional acoustic information, especially at low frequencies. However, the benefit may be reduced, or usage discouraged when acoustic inputs at devices are unbalanced.
Electroacoustic verification is an important step in the first fitting HA and has been used in the CI evaluating candidates. With the expansion of CI criteria, mainly in asymmetrical hearing losses, it is relevant to have protocols for better auditory residue profit and devices balancing, allowing the increment of binaural skills.
Objective:The study aim was to identify the contribution of loudness balancing between CI and HA with speech stimulus in bimodal stimulation users, and to verify the impact of balancing on SII and speech recognition tests results.
Method: Bimodal stimulation users, with at least one year of CI use were recruited for the balancing protocol with speech stimulus, in which the recorded Ling Sounds were presented at 65dBHL during hearing aid fitting. Procedures included electroacoustic verification aiming to balance the loudness of inputs on both devices. Results of speech recognition tests in quiet and in noise (signal-to-noise ratio at +10dBHL), Speech, Spatial and Qualities of Hearing Scale questionnaire - short version (SSQ12) and SII values before and after balancing using the Wilcoxon test were compared, adopting p<0,05 %.
Results: Nine bimodal users participated, with ages ranging from 11 to 78. Before balancing, Ling sounds were judged as equal between the devices in 53.71% and after, in 96.3% of the presentations. There was a statistically significant difference in the speech sounds perception /u/ (p=0.0277), /i/ (p=0.0431) and /sh/ (p=0.0431) after HA fitting and in speech recognition test in noise (p=0.026). There was no significant change in SII values at all levels (55dB, 65dB and 75dB) and in the SSQ-12.
Conclusion: Speech stimulus proved to be useful in loudness balancing. Performance improvement in background noise suggests that bimodal balancing is beneficial in a challenging listening situation, although there was no impact on the SII values.

**Background:** In unilateral cochlear implant (CI) users, hearing aid (HA) usage in the non-implanted ear is important to provide additional acoustic information, especially at low frequencies. However, the benefit may be reduced, or usage discouraged when acoustic inputs at devices are unbalanced.
Electroacoustic verification is an important step in the first fitting HA and has been used in the CI evaluating candidates. With the expansion of CI criteria, mainly in asymmetrical hearing losses, it is relevant to have protocols for better auditory residue profit and devices balancing, allowing the increment of binaural skills.
**Objective:**The study aim was to identify the contribution of loudness balancing between CI and HA with speech stimulus in bimodal stimulation users, and to verify the impact of balancing on SII and speech recognition tests results.
**Method:** Bimodal stimulation users, with at least one year of CI use were recruited for the balancing protocol with speech stimulus, in which the recorded Ling Sounds were presented at 65dBHL during hearing aid fitting. Procedures included electroacoustic verification aiming to balance the loudness of inputs on both devices. Results of speech recognition tests in quiet and in noise (signal-to-noise ratio at +10dBHL), Speech, Spatial and Qualities of Hearing Scale questionnaire - short version (SSQ12) and SII values before and after balancing using the Wilcoxon test were compared, adopting _p_<0,05 %.
**Results:** Nine bimodal users participated, with ages ranging from 11 to 78. Before balancing, Ling sounds were judged as equal between the devices in 53.71% and after, in 96.3% of the presentations. There was a statistically significant difference in the speech sounds perception /u/ (p=0.0277), /i/ (p=0.0431) and /sh/ (p=0.0431) after HA fitting and in speech recognition test in noise (p=0.026). There was no significant change in SII values at all levels (55dB, 65dB and 75dB) and in the SSQ-12.
**Conclusion:** Speech stimulus proved to be useful in loudness balancing. Performance improvement in background noise suggests that bimodal balancing is beneficial in a challenging listening situation, although there was no impact on the SII values.

Use of speech stimuli associated with the speech intelligibility index in a protocol for balancing hearing devices in bimodal stimulation users

It is with great pleasure and enthusiasm, that on behalf of the Cochlear Implant centers of the Radboud UMC in Nijmegen and Erasmus MC Sophia Children’s Hospital in Rotterdam to invite you to attend the 16th European Symposium on Pediatric Cochlear Implantation to Rotterdam, the Netherlands in 2023.

Yours sincerely, on behalf of the CI Centers at Radboud UMC and Erasmus MC,