Combining current focusing and steering in a cochlear implant processing strategy.

Objective: To evaluate the benefit of combined current focusing and steering to speech recognition in noise with cochlear implants (CIs).

Design: Combined current focusing and steering was implemented using focused partial tripolar (pTP) mode with two current steering ranges. The two pTPsteering strategies were compared to a monopolar (MP) strategy without current focusing or steering and a pTP strategy with only current focusing using the Hearing in Noise Test.

WNT3A Promotes Neuronal Regeneration upon Traumatic Brain Injury.

The treatment of traumatic brain injury (TBI) remains a challenge due to limited knowledge about the mechanisms underlying neuronal regeneration. This current study compared the expression of genes during regeneration of injured cortical neurons. Recombinant WNT3A showed positive effect in promoting neuronal regeneration via in vitro, ex vivo, and in vivo TBI models.

Symmetric Electrode Spanning Narrows the Excitation Patterns of Partial Tripolar Stimuli in Cochlear Implants.

In cochlear implants (CIs), standard partial tripolar (pTP) mode reduces current spread by returning a fraction of the current to two adjacent flanking electrodes within the cochlea. Symmetric electrode spanning (i.e.

Excitation Patterns of Standard and Steered Partial Tripolar Stimuli in Cochlear Implants.

Current steering in partial tripolar (pTP) mode has been shown to improve pitch perception and spectral resolution with cochlear implants (CIs). In this mode, a fraction (σ) of the main electrode current is returned within the cochlea and steered between the basal and apical flanking electrodes (with a proportion of α and 1 - α, respectively). Pitch generally decreases when α increases from 0 to 1, although the salience of pitch change varies across CI users.

Melodic interval perception by normal-hearing listeners and cochlear implant users.

The perception of melodic intervals (sequential pitch differences) is essential to music perception. This study tested melodic interval perception in normal-hearing (NH) listeners and cochlear implant (CI) users. Melodic interval ranking was tested using an adaptive procedure.

Electrode spanning with partial tripolar stimulation mode in cochlear implants.

The perceptual effects of electrode spanning (i.e., the use of nonadjacent return electrodes) in partial tripolar (pTP) mode were tested on a main electrode EL8 in five cochlear implant (CI) users.

Contour identification with pitch and loudness cues using cochlear implants.

Different from speech, pitch and loudness cues may or may not co-vary in music. Cochlear implant (CI) users with poor pitch perception may use loudness contour cues more than normal-hearing (NH) listeners. Contour identification was tested in CI users and NH listeners; the five-note contours contained either pitch cues alone, loudness cues alone, or both.

Current steering with partial tripolar stimulation mode in cochlear implants.

The large spread of excitation is a major cause of poor spectral resolution for cochlear implant (CI) users. Partial tripolar (pTP) mode has been proposed to reduce current spread by returning an equally distributed fraction (0.5 × σ) of current to two flanking electrodes and the rest to an extra-cochlear ground.