Evaluation of an English language phoneme-based imagined speech brain computer interface with low-cost electroencephalography.

Introduction: Paralyzed and physically impaired patients face communication difficulties, even when they are mentally coherent and aware. Electroencephalographic (EEG) brain-computer interfaces (BCIs) offer a potential communication method for these people without invasive surgery or physical device controls.

Methods: Although virtual keyboard protocols are well documented in EEG BCI paradigms, these implementations are visually taxing and fatiguing.

Evaluation of a spectral subtraction strategy to suppress reverberant energy in cochlear implant devices.

The smearing effects of room reverberation can significantly impair the ability of cochlear implant (CI) listeners to understand speech. To ameliorate the effects of reverberation, current dereverberation algorithms focus on recovering the direct sound from the reverberated signal by inverse filtering the reverberation process. This contribution describes and evaluates a spectral subtraction (SS) strategy capable of suppressing late reflections.

The perception of telephone-processed speech by combined electric and acoustic stimulation.

This study assesses the effects of adding low- or high-frequency information to the band-limited telephone-processed speech on bimodal listeners' telephone speech perception in quiet environments. In the proposed experiments, bimodal users were presented under quiet listening conditions with wideband speech (WB), bandpass-filtered telephone speech (300-3,400 Hz, BP), high-pass filtered speech (f > 300 Hz, HP, i.e.

Effects of low harmonics on tone identification in natural and vocoded speech.

This study investigated the contribution of low-frequency harmonics to identifying Mandarin tones in natural and vocoded speech in quiet and noisy conditions. Results showed that low-frequency harmonics of natural speech led to highly accurate tone identification; however, for vocoded speech, low-frequency harmonics yielded lower tone identification than stimuli with full harmonics, except for tone 4. Analysis of the correlation between tone accuracy and the amplitude-F0 correlation index suggested that "more" speech contents (i.

The effects of binaural spectral resolution mismatch on Mandarin speech perception in simulated electric hearing.

This study assessed the effects of binaural spectral resolution mismatch on the intelligibility of Mandarin speech in noise using bilateral cochlear implant simulations. Noise-vocoded Mandarin speech, corrupted by speech-shaped noise at 0 and 5 dB signal-to-noise ratios, were presented unilaterally or bilaterally to normal-hearing listeners with mismatched spectral resolution between ears. Significant binaural benefits for Mandarin speech recognition were observed only with matched spectral resolution between ears.