Novel Coding Strategies for Children With Cochlear Implants

AIM 2 - Stimuli will be presented on one of three electrodes (apical, middle, and basal) at an amplitude between 10 and 100% dynamic range in µAs in 10% dynamic range steps. Stimulation will be delivered at a rate of 1000 pps. The process will be repeated in random order until 20 loudness estimates are obtained for each stimulus (3 electrodes x 2 rates x 10 amplitudes) for each subject. The dynamic range will be determined by measuring the maximum acceptable loudness (MAL) and threshold for each of the stimuli. MAL will be measured by slowly raising the current level for each stimulus until the subject reports that it is as loud as they are willing to accept without becoming uncomfortably loud.

AIM 1 - MDT will be set at 150 Hz. Testing will be conducted in soundfield in a sound booth at 60 dB Sound Pressure Level (SPL) while the participant listens with both implants adjusted to user setting.

Aim3 - Spectral-temporally modulated ripple test (SMRT), Quick Spectral Modulation Detection (QSMD), Modulation Detection, Gap Detection. CNC words will be set in quiet and Az-Bio/BabyBio sentences in quiet and multi-talker babble (+10 and +5 dB SNR) using both the subject's clinical map and the new reduced channels map. Tests will be presented in the soundfield at 60 dB SPL

Aim 1- Spectral resolution will be tested using frequency allocations consisting of the full default clinical range as well as the subject's clinical frequency allocation if they differ. For Hybrid electrode users in which electrode contacts are closer in proximity in the cochlea, maps with a frequency allocation of 938-7938 Hz will also be tested in that it will closely approximate the frequency spacing of a Nucleus Contour Advance electrode array. Spectral resolution will be measured with three repetitions of the SMRT and one repetition of the QSMD test. Testing will be presented at 60 dB SPL in the soundfield with the acoustic ear plugged and muffed.