Related Experiment Video
Updated: Mar 24, 2026
07:34
A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions
Published on: March 25, 2014
10.3K
Pulse-spreading harmonic complex as an alternative carrier for vocoder simulations of cochlear implants
Quentin Mesnildrey1, Gaston Hilkhuysen1, Olivier Macherey1
1LMA-CNRS, UPR 7051, Aix-Marseille Université, Centrale Marseille, 4 impasse Nikola TESLA CS 40006, F-13453, Marseille Cedex 13, France.
The Journal of the Acoustical Society of America
|March 4, 2016
Summary
Pulse-spreading harmonic complexes (PSHCs) offer a new way to simulate cochlear implant (CI) sound processing. PSHC-vocoders provide a middle ground between sine- and noise-vocoders for speech recognition in noise.
Area of Science:
- Auditory Neuroscience
- Speech Processing
- Bioacoustics
Background:
- Current vocoders (sine- and noise-carriers) imperfectly simulate cochlear implant (CI) acoustic information.
- Sine-vocoders lack the broad excitation spread of CIs, while noise-vocoders introduce unwanted modulations.
Purpose of the Study:
- To introduce pulse-spreading harmonic complexes (PSHCs) as a novel acoustic carrier for vocoders.
- To evaluate PSHC-vocoders' effectiveness in simulating CI sound processing for speech recognition.
Main Methods:
- Developed PSHC-vocoders as an alternative acoustic carrier.
- Measured sentence-in-noise recognition in 12 normal-hearing subjects.
- Compared PSHC-vocoders against traditional sine- and noise-vocoders.
Main Results:
- Speech reception thresholds varied based on vocoder type, reflecting intrinsic modulations.
- PSHC-vocoders yielded higher thresholds than sine-vocoders, indicating less effective simulation.
- PSHC-vocoders yielded lower thresholds than noise-vocoders, suggesting a better balance of acoustic features.
Conclusions:
- PSHCs represent a promising alternative carrier for vocoder simulations of cochlear implant (CI) signal processing.
- PSHC-vocoders offer an intermediate acoustic simulation between sine- and noise-vocoders.
- Further research can refine PSHC-vocoders for improved CI speech perception studies.
Related Concept Videos
01:17Impulse Response
853
The impulse response is the system's reaction to an input impulse. In an RC circuit, the voltage source is the input, and the capacitor's voltage is the output. The system's state and output response before and after input excitation are distinctly defined.
Kirchhoff's law forms an input signal equation, with the capacitor's current and voltage providing the output. Substituting the current and dividing by RC yields a differential equation. The output for an impulse input is the impulse...
Kirchhoff's law forms an input signal equation, with the capacitor's current and voltage providing the output. Substituting the current and dividing by RC yields a differential equation. The output for an impulse input is the impulse...
853
01:18Sinusoidal Sources
1.3K
Direct current (DC) refers to an electric current that flows in a single direction, maintaining a constant polarity. This is in contrast to alternating current (AC), which periodically changes its direction and magnitude. AC forms the backbone of modern electricity transmission and distribution systems due to its efficient long-distance transmission capabilities.
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
1.3K
01:17Sound as Pressure Waves
4.8K
Sound waves, which are longitudinal waves, can be modeled as the displacement amplitude varying as a function of the spatial and temporal coordinates. As a column of the medium is displaced, its successive columns are also displaced. As the successive displacements differ relatively, a pressure difference with the surrounding pressure is created. The gauge pressure varies across the medium.
The pressure fluctuation depends on the difference in displacements between the successive points in the...
The pressure fluctuation depends on the difference in displacements between the successive points in the...
4.8K
01:17Bandpass Sampling
609
In signal processing, bandpass sampling is an effective technique for sampling signals that have most of their energy concentrated within a narrow frequency band. This type of signal is known as a bandpass signal. The key principle of bandpass sampling involves sampling the signal at a rate that is greater than twice the signal's bandwidth to prevent aliasing.
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2....
609
01:13The Cochlea
52.4K
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
52.4K
01:11Sampling Continuous Time Signal
824
In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points.
In the...
In the...
824