Cochlear Implant Electrode Stimulation for Polyphonic Pitch

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Cochlear implants struggle to accurately process polyphonic music, failing to account for the place pitch and rate pitch mechanisms of the cochlea, leading to impaired perception of multiple simultaneous pitches.

Innovation Solution

A cochlear implant system with an electrode array that stimulates electrodes in an interleaved arrangement using modulated frequency signals, applying patient-specific mappings to enhance polyphonic pitch perception by modulating the amplitude of pulse currents with different sinusoidal frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional cochlear implant coding strategies are used, then the device complexity is reduced and ease of operation is improved, but the ability to perceive polyphonic pitch is lost

Engineering Contradiction:
Improveease of operationVSAvoidpolyphonic pitch perception
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The electrode array is divided into multiple electrode contacts, each associated with a specific frequency band. The signal processing system segments the input sound signal into multiple frequency components and maps them to different electrode contacts, enabling the implant to represent multiple simultaneous pitches through distributed stimulation of segmented cochlear regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the stimulation pattern by varying the frequency and amplitude of electrical pulses delivered to different electrode contacts based on the temporal and spectral characteristics of the input sound signal, allowing flexible representation of polyphonic pitch structures in real-time

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple modulated frequency signals are applied to electrodes simultaneously, then polyphonic pitch perception is enhanced, but the device complexity increases

Engineering Contradiction:
Improvepolyphonic pitch perceptionVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The complex task of representing polyphonic pitch is segmented across multiple electrode contacts, each handling a specific frequency component. This distribution allows the system to achieve polyphonic capability without requiring a single overly complex processing or stimulation mechanism

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode array and signal processing system are designed to handle multiple functions simultaneously - representing different frequency bands, temporal patterns, and pitch structures through the same hardware platform, making the system universally applicable to various audio processing tasks

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the perception of polyphonic pitch by creating polyphonic place and rate pitch sensations, improving music perception in cochlear implant users.

Implementation Method 1

a cochlear implant with an implanted stimulation electrode can electrically stimulate auditory nerve tissue with small currents delivered by multiple electrode contacts distributed along the electrode

Methodology Applied
Scientific EffectElectrical stimulation: Conduction (electrical)

Implementation Method 2

the fluidfilled cochlea 104 functions as a transducer to generate electric pulses which are transmitted to the cochlear nerve 113

Methodology Applied
Scientific EffectMechanical transduction:

Data Source

PatentEP4021561B1Polyphonic pitch enhancement in a cochlear implant
Publication Date: 2025.10.15 MED EL ELEKTROMEDIZINISCHE GERAETE GMBH
  • EP4021561B1 patent drawingFigure 1
  • EP4021561B1 patent drawingFigure 2
  • EP4021561B1 patent drawingFigure 3

AI summary

A cochlear implant system for processing polyphonic pitch includes an electrode array for implanting in a cochlea of a patient. The electrode array includes a first set of electrodes, where each electrode of the first set is for implanting on a first region of the cochlea. The electrode array also includes a second set of electrodes, where each electrode of the second set is for implanting on a second region of the cochlea. The system also includes a sound processor configured to capture a sound signal having polyphonic pitch. For each electrode of the first set and second set, the speech processor generates at least two different modulated frequency signals from the sound signal, such that each of the modulated frequency signals corresponds to a different pitch in the sound signal. The speech processor stimulates the electrode by simultaneously applying the at least two different modulated frequency signals.