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Recognition and understanding of sign language can aid communication between nondeaf and deaf people. Recently, research groups have developed sign language recognition algorithms using multiple sensors. However, in everyday life, minimizing the number of sensors would still require the use of a sign language interpreter. In this study, a sign language classification method was developed using an accelerometer to recognize the Korean sign language alphabet. The accelerometer is worn on the proximal phalanx of the index finger of the dominant hand. Triaxial accelerometer signals were used to segment the sign gesture (i.e., the time period when a user is performing a sign) and recognize the 31 Korean sign language letters (producing a chance level of 3.2%). The vector sum of the accelerometer signals was used to segment the sign gesture with 98.9% segmentation accuracy, which is comparable to that of previous multisensor systems (99.49%). The system was able to classify the Korean sign language alphabet with 92.2% accuracy. The recognition accuracy of this approach was found to be higher than that of a previous work in the same sign language alphabet classification task. The findings demonstrate that a single-sensor accelerometer with simple features can be reliably used for Korean sign language alphabet recognition in everyday life.
Youngmin Na; Hyejin Yang; Jihwan Woo. Classification of the Korean Sign Language Alphabet Using an Accelerometer with a Support Vector Machine. Journal of Sensors 2021, 2021, 1 -10.
AMA StyleYoungmin Na, Hyejin Yang, Jihwan Woo. Classification of the Korean Sign Language Alphabet Using an Accelerometer with a Support Vector Machine. Journal of Sensors. 2021; 2021 ():1-10.
Chicago/Turabian StyleYoungmin Na; Hyejin Yang; Jihwan Woo. 2021. "Classification of the Korean Sign Language Alphabet Using an Accelerometer with a Support Vector Machine." Journal of Sensors 2021, no. : 1-10.
Spectral ripple discrimination (SRD) has been widely used to evaluate the spectral resolution in cochlear implant (CI) recipients based on its strong correlation with speech perception performance. However, despite its usefulness for predicting speech perception outcomes, SRD performance exhibits large across-subject variabilities even among subjects implanted with the same CIs and sound processors. The potential factors of this observation include current spread, nerve survival, and CI mapping. Previous studies have found that the spectral resolution reduces with increasing distance of the stimulation electrode from the auditory nerve fibers (ANFs), attributable to increasing current spread. However, it remains unclear whether the spread of excitation is the only cause of the observation, or whether other factors such as temporal interaction also contribute to it. In this study, we used a computational model to investigate channel interaction upon non-simultaneous stimulation with respect to the electrode–ANF distance, and evaluated the SRD performance for five electrode–ANF distances. The SRD performance was determined based on the similarity between two neurograms in response to standard and inverted stimuli and used to evaluate the spectral resolution in the computational model. The spread of excitation was observed to increase with increasing electrode–ANF distance, consistent with previous findings. Additionally, the preceding pulses delivered from neighboring channels induced a channel interaction that either inhibited or facilitated the neural responses to subsequent pulses depending on the electrode–ANF distance. The SRD performance was also found to decrease with increasing electrode–ANF distance. The findings of this study suggest that variation of the neural responses (inhibition or facilitation) with the electrode–ANF distance in CI users may cause spectral smearing, and hence poor spectral resolution. A computational model such as that used in this study is a useful tool for understanding the neural factors related to CI outcomes, such as cannot be accomplished by behavioral studies alone.
Hyejin Yang; Jong Ho Won; Inyong Choi; Jihwan Woo. A computational study to model the effect of electrode-to-auditory nerve fiber distance on spectral resolution in cochlear implant. PLOS ONE 2020, 15, e0236784 .
AMA StyleHyejin Yang, Jong Ho Won, Inyong Choi, Jihwan Woo. A computational study to model the effect of electrode-to-auditory nerve fiber distance on spectral resolution in cochlear implant. PLOS ONE. 2020; 15 (8):e0236784.
Chicago/Turabian StyleHyejin Yang; Jong Ho Won; Inyong Choi; Jihwan Woo. 2020. "A computational study to model the effect of electrode-to-auditory nerve fiber distance on spectral resolution in cochlear implant." PLOS ONE 15, no. 8: e0236784.
Interest in electrocochleography (ECoG) has recently resurged as a potential tool to assess peripheral auditory function in cochlear implant (CI) users. ECoG recordings can be evoked using acoustic stimulation and recorded from an extra- or intra-cochlear electrode in CI users. Recordings reflect contributions from cochlear hair cells and the auditory nerve. We recently demonstrated the feasibility of using Custom Sound EP (clinically available software) to record ECoG responses in Nucleus Hybrid CI users with preserved acoustic hearing in the implanted ear (Abbas et al, 2017). While successful, the recording procedures were time intensive, limiting clinical applications. The current report describes how we improved data collection efficiency by writing custom software using Python programming language. The software interfaced with Nucleus Implant Communicator (NIC) routines to record responses from an intracochlear electrode. ECoG responses were recorded in eight CI users with preserved acoustic hearing using Custom Sound EP and the Python-based software. Responses were similar across both recording systems, but the recording time decreased significantly using the Python-based software. Seven additional CI users underwent repeated testing using the Python-based software and showed high test-retest reliability. The improved efficiency and high reliability increases the likelihood of translating intracochlear ECoG to clinical practice.
Viral Tejani; Paul J. Abbas; Carolyn J. Brown; Jihwan Woo. An improved method of obtaining electrocochleography recordings from Nucleus Hybrid cochlear implant users. Hearing Research 2019, 373, 113 -120.
AMA StyleViral Tejani, Paul J. Abbas, Carolyn J. Brown, Jihwan Woo. An improved method of obtaining electrocochleography recordings from Nucleus Hybrid cochlear implant users. Hearing Research. 2019; 373 ():113-120.
Chicago/Turabian StyleViral Tejani; Paul J. Abbas; Carolyn J. Brown; Jihwan Woo. 2019. "An improved method of obtaining electrocochleography recordings from Nucleus Hybrid cochlear implant users." Hearing Research 373, no. : 113-120.
Classification of spoken word-evoked potentials is useful for both neuroscientific and clinical applications including brain-computer interfaces (BCIs). By evaluating whether adopting a biology-based structure improves a classifier’s accuracy, we can investigate the importance of such structure in human brain circuitry, and advance BCI performance. In this study, we propose a semantic-hierarchical structure for classifying spoken word-evoked cortical responses. The proposed structure decodes the semantic grouping of the words first (e.g., a body part vs. a number) and then decodes which exact word was heard. The proposed classifier structure exhibited a consistent ~10% improvement of classification accuracy when compared with a non-hierarchical structure. Our result provides a tool for investigating the neural representation of semantic hierarchy and the acoustic properties of spoken words in human brains. Our results suggest an improved algorithm for BCIs operated by decoding heard, and possibly imagined, words.
Youngmin Na; Inyong Choi; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography. Journal of Neuroscience Methods 2018, 311, 253 -258.
AMA StyleYoungmin Na, Inyong Choi, Dong Pyo Jang, Joong Koo Kang, Jihwan Woo. Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography. Journal of Neuroscience Methods. 2018; 311 ():253-258.
Chicago/Turabian StyleYoungmin Na; Inyong Choi; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. 2018. "Semantic-hierarchical model improves classification of spoken-word evoked electrocorticography." Journal of Neuroscience Methods 311, no. : 253-258.
Generalized tonic-clonic seizures (GTCSs) can be underestimated and can also increase mortality rates. The monitoring devices used to detect GTCS events in daily life are very helpful for early intervention and precise estimation of seizure events. Several studies have introduced methods for GTCS detection using an accelerometer (ACM), electromyography, or electroencephalography. However, these studies need to be improved with respect to accuracy and user convenience. This study proposes the use of an ACM banded to the wrist and spectral analysis of ACM data to detect GTCS in daily life. The spectral weight function dependent on GTCS was used to compute a GTCS-correlated score that can effectively discriminate between GTCS and normal movement. Compared to the performance of the previous temporal method, which used a standard deviation method, the spectral analysis method resulted in better sensitivity and fewer false positive alerts. Finally, the spectral analysis method can be implemented in a GTCS monitoring device using an ACM and can provide early alerts to caregivers to prevent risks associated with GTCS.
Hyo Sung Joo; Su-Hyun Han; Jongshill Lee; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures. Sensors 2017, 17, 481 .
AMA StyleHyo Sung Joo, Su-Hyun Han, Jongshill Lee, Dong Pyo Jang, Joong Koo Kang, Jihwan Woo. Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures. Sensors. 2017; 17 (3):481.
Chicago/Turabian StyleHyo Sung Joo; Su-Hyun Han; Jongshill Lee; Dong Pyo Jang; Joong Koo Kang; Jihwan Woo. 2017. "Spectral Analysis of Acceleration Data for Detection of Generalized Tonic-Clonic Seizures." Sensors 17, no. 3: 481.
Hyejin Yang; Seonyoung An; Jaehyeon Jeong; Inyong Choi; Jihwan Woo. Automatic Directional-gain Control for Binaural Hearing Aids using Geomagnetic Sensors. Journal of Biomedical Engineering Research 2016, 37, 209 -214.
AMA StyleHyejin Yang, Seonyoung An, Jaehyeon Jeong, Inyong Choi, Jihwan Woo. Automatic Directional-gain Control for Binaural Hearing Aids using Geomagnetic Sensors. Journal of Biomedical Engineering Research. 2016; 37 (6):209-214.
Chicago/Turabian StyleHyejin Yang; Seonyoung An; Jaehyeon Jeong; Inyong Choi; Jihwan Woo. 2016. "Automatic Directional-gain Control for Binaural Hearing Aids using Geomagnetic Sensors." Journal of Biomedical Engineering Research 37, no. 6: 209-214.
Cochlear implant systems restore the sense of sound by stimulating auditory nerve fibers (ANFs) with surgically implanted electrodes. Neural activity elicited by electrical pulse-trains conveys sound information to the brain. Thus, it is important to understand how ANFs produce the temporal sequence of neural activity in response to sinusoidally amplitude-modulated (SAM) pulse-trains with a rate of 5,000 pulses/s. In this study, we evaluated the effects of axon diameter (1.2 to 4.6 μm) and the electrode-to-axon distance (0.525 to 1.00 mm) on the response to 100 Hz SAM pulse-trains using a computational ANF model. The model uses a Hodgkin-Huxley computation that incorporates the kinetics of sodium and potassium channels and an adaptation component. Simulated responses were analyzed by computing vector strength (VS) and the amplitude of the fast Fourier transform component at the modulation component (F0 amplitude). Axon diameter significantly influenced neural responses to SAM pulse-train stimuli. As the axon diameter increased, the VS and F0 amplitude increased. However, the VS and F0 amplitude were less influenced by the electrode-to-axon distance. Finally, we concluded that larger-diameter ANFs could more precisely convey temporal information of speech sound.
Hyejin Yang; Jihwan Woo. Effect of axon diameter and electrode position on responses to sinusoidally amplitude-modulated electric pulse-train stimuli. Biomedical Engineering Letters 2015, 5, 124 -130.
AMA StyleHyejin Yang, Jihwan Woo. Effect of axon diameter and electrode position on responses to sinusoidally amplitude-modulated electric pulse-train stimuli. Biomedical Engineering Letters. 2015; 5 (2):124-130.
Chicago/Turabian StyleHyejin Yang; Jihwan Woo. 2015. "Effect of axon diameter and electrode position on responses to sinusoidally amplitude-modulated electric pulse-train stimuli." Biomedical Engineering Letters 5, no. 2: 124-130.
A cochlear implant (CI) is an auditory prosthesis that enables hearing by providing electrical stimuli through an electrode array. It has been previously established that the electrode position can influence CI performance. Thus, electrode position should be considered in order to achieve better CI results. This paper describes how the electrode position influences the auditory nerve fiber (ANF) response to either a single pulse or low- (250 pulses/s) and high-rate (5,000 pulses/s) pulse-trains using a computational model. The field potential in the cochlea was calculated using a three-dimensional finite-element model, and the ANF response was simulated using a biophysical ANF model. The effects were evaluated in terms of the dynamic range, stochasticity, and spike excitation pattern. The relative spread, threshold, jitter, and initiated node were analyzed for single-pulse response; and the dynamic range, threshold, initiated node, and interspike interval were analyzed for pulse-train stimuli responses. Electrode position was found to significantly affect the spatiotemporal pattern of the ANF response, and this effect was significantly dependent on the stimulus rate. We believe that these modeling results can provide guidance regarding perimodiolar and lateral insertion of CIs in clinical settings and help understand CI performance.
Soojin Kang; Tanmoy Chwodhury; Il Joon Moon; Sung Hwa Hong; Hyejin Yang; Jong Ho Won; Jihwan Woo. Effects of Electrode Position on Spatiotemporal Auditory Nerve Fiber Responses: A 3D Computational Model Study. Computational and Mathematical Methods in Medicine 2015, 2015, 1 -13.
AMA StyleSoojin Kang, Tanmoy Chwodhury, Il Joon Moon, Sung Hwa Hong, Hyejin Yang, Jong Ho Won, Jihwan Woo. Effects of Electrode Position on Spatiotemporal Auditory Nerve Fiber Responses: A 3D Computational Model Study. Computational and Mathematical Methods in Medicine. 2015; 2015 (10):1-13.
Chicago/Turabian StyleSoojin Kang; Tanmoy Chwodhury; Il Joon Moon; Sung Hwa Hong; Hyejin Yang; Jong Ho Won; Jihwan Woo. 2015. "Effects of Electrode Position on Spatiotemporal Auditory Nerve Fiber Responses: A 3D Computational Model Study." Computational and Mathematical Methods in Medicine 2015, no. 10: 1-13.
It is important and recommended to detect hearing loss as soon as possible. If it is found early, proper treatment may help improve hearing and reduce the negative consequences of hearing loss. In this study, we developed smartphone-based hearing screening methods that can ubiquitously test hearing. However, environmental noise generally results in the loss of ear sensitivity, which causes a hearing threshold shift (HTS). To overcome this limitation in the hearing screening location, we developed a correction algorithm to reduce the HTS effect. A built-in microphone and headphone were calibrated to provide the standard units of measure. The HTSs in the presence of either white or babble noise were systematically investigated to determine the mean HTS as a function of noise level. When the hearing screening application runs, the smartphone automatically measures the environmental noise and provides the HTS value to correct the hearing threshold. A comparison to pure tone audiometry shows that this hearing screening method in the presence of noise could closely estimate the hearing threshold. We expect that the proposed ubiquitous hearing test method could be used as a simple hearing screening tool and could alert the user if they suffer from hearing loss.
Youngmin Na; Hyo Sung Joo; Hyejin Yang; Soojin Kang; Sung Hwa Hong; Jihwan Woo. Smartphone-Based Hearing Screening in Noisy Environments. Sensors 2014, 14, 10346 -10360.
AMA StyleYoungmin Na, Hyo Sung Joo, Hyejin Yang, Soojin Kang, Sung Hwa Hong, Jihwan Woo. Smartphone-Based Hearing Screening in Noisy Environments. Sensors. 2014; 14 (6):10346-10360.
Chicago/Turabian StyleYoungmin Na; Hyo Sung Joo; Hyejin Yang; Soojin Kang; Sung Hwa Hong; Jihwan Woo. 2014. "Smartphone-Based Hearing Screening in Noisy Environments." Sensors 14, no. 6: 10346-10360.
Jae-Ryong Kim; Bong-Sik Shin; Sung-Wook Jeong; Jihwan Woo; Lee-Suk Kim. The Relationship between Thresholds of Electrically Evoked Compound Action Potential and Speech Perception in Children with Cochlear Implants. Korean Journal of Otorhinolaryngology-Head and Neck Surgery 2011, 54, 1 .
AMA StyleJae-Ryong Kim, Bong-Sik Shin, Sung-Wook Jeong, Jihwan Woo, Lee-Suk Kim. The Relationship between Thresholds of Electrically Evoked Compound Action Potential and Speech Perception in Children with Cochlear Implants. Korean Journal of Otorhinolaryngology-Head and Neck Surgery. 2011; 54 (10):1.
Chicago/Turabian StyleJae-Ryong Kim; Bong-Sik Shin; Sung-Wook Jeong; Jihwan Woo; Lee-Suk Kim. 2011. "The Relationship between Thresholds of Electrically Evoked Compound Action Potential and Speech Perception in Children with Cochlear Implants." Korean Journal of Otorhinolaryngology-Head and Neck Surgery 54, no. 10: 1.
Electric stimuli can prosthetically excite auditory nerve fibers to partially restore sensory function to individuals impaired by profound or severe hearing loss. While basic response properties of electrically stimulated auditory nerve fibers (ANF) are known, responses to complex, time-changing stimuli used clinically are inadequately understood. We report that forward-masker pulse trains can enhance and reduce ANF responsiveness to subsequent stimuli and the novel observation that sub-threshold (nonspike-evoking) electric trains can reduce responsiveness to subsequent pulse-train stimuli. The effect is observed in the responses of cat ANFs and shown by a computational biophysical ANF model that simulates rate adaptation through integration of external potassium cation (K) channels. Both low-threshold (i.e., Klt) and high-threshold (Kht) channels were simulated at each node of Ranvier. Model versions without Klt channels did not produce the sub-threshold effect. These results suggest that some such accumulation mechanism, along with Klt channels, may underlie sub-threshold masking observed in cat ANF responses. As multichannel auditory prostheses typically present sub-threshold stimuli to various ANF subsets, there is clear relevance of these findings to clinical situations.
Charles A. Miller; Jihwan Woo; Paul J. Abbas; Ning Hu; Barbara K. Robinson. Neural Masking by Sub-threshold Electric Stimuli: Animal and Computer Model Results. Journal of the Association for Research in Otolaryngology 2010, 12, 219 -232.
AMA StyleCharles A. Miller, Jihwan Woo, Paul J. Abbas, Ning Hu, Barbara K. Robinson. Neural Masking by Sub-threshold Electric Stimuli: Animal and Computer Model Results. Journal of the Association for Research in Otolaryngology. 2010; 12 (2):219-232.
Chicago/Turabian StyleCharles A. Miller; Jihwan Woo; Paul J. Abbas; Ning Hu; Barbara K. Robinson. 2010. "Neural Masking by Sub-threshold Electric Stimuli: Animal and Computer Model Results." Journal of the Association for Research in Otolaryngology 12, no. 2: 219-232.
Response rates of auditory nerve fibers (ANFs) to electric pulse trains change over time, reflecting substantial spike-rate adaptation that depends on stimulus parameters. We hypothesize that adaptation affects the representation of amplitude-modulated pulse trains used by cochlear prostheses to transmit speech information to the auditory system. We recorded cat ANF responses to sinusoidally amplitude-modulated (SAM) trains with 5,000 pulse/s carriers. Stimuli delivered by a monopolar intracochlear electrode had fixed modulation frequency (100 Hz) and depth (10%). ANF responses were assessed by spike-rate measures, while representation of modulation was evaluated by vector strength (VS) and the fundamental component of the fast Fourier transform (F0 amplitude). These measures were assessed across the 400 ms duration of pulse-train stimuli, a duration relevant to speech stimuli. Different stimulus levels were explored and responses were categorized into four spike-rate groups to assess level effects across ANFs. The temporal pattern of rate adaptation to modulated trains was similar to that of unmodulated trains, but with less rate adaptation. VS to the modulator increased over time and tended to saturate at lower spike rates, while F0 amplitude typically decreased over time for low driven rates and increased for higher driven rates. VS at moderate and high spike rates and degree of F0 amplitude temporal changes at low and moderate spike rates were positively correlated with the degree of rate adaptation. Thus, high-rate carriers will modify the ANF representation of the modulator over time. As the VS and F0 measures were sensitive to adaptation-related changes over different spike-rate ranges, there is value in assessing both measures.
Ning Hu; Charles Miller; Paul J. Abbas; Barbara K. Robinson; Jihwan Woo. Changes in Auditory Nerve Responses Across the Duration of Sinusoidally Amplitude-Modulated Electric Pulse-Train Stimuli. Journal of the Association for Research in Otolaryngology 2010, 11, 641 -656.
AMA StyleNing Hu, Charles Miller, Paul J. Abbas, Barbara K. Robinson, Jihwan Woo. Changes in Auditory Nerve Responses Across the Duration of Sinusoidally Amplitude-Modulated Electric Pulse-Train Stimuli. Journal of the Association for Research in Otolaryngology. 2010; 11 (4):641-656.
Chicago/Turabian StyleNing Hu; Charles Miller; Paul J. Abbas; Barbara K. Robinson; Jihwan Woo. 2010. "Changes in Auditory Nerve Responses Across the Duration of Sinusoidally Amplitude-Modulated Electric Pulse-Train Stimuli." Journal of the Association for Research in Otolaryngology 11, no. 4: 641-656.
This paper describes results from a stochastic computational neuron model that simulates the effects of rate adaptation on the responses to electrical stimulation in the form of pulse trains. We recently reported results from a single-node computational model that included a novel element that tracks external potassium ion concentration so as to modify membrane voltage and cause adaptation-like responses. Here, we report on an improved version of the model that incorporates the anatomical components of a complete feline auditory nerve fiber (ANF) so that conduction velocity and effects of manipulating the site of excitation can be evaluated. Model results demonstrate rate adaptation and changes in spike amplitude similar to those reported for feline ANFs. Changing the site of excitation from a central to a peripheral axonal site resulted in plausible changes in latency and relative spread (i.e., dynamic range). Also, increasing the distance between a modeled ANF and a stimulus electrode tended to decrease the degree of rate adaptation observed in pulse-train responses. This effect was clearly observed for high-rate (5,000 pulse/s) trains but not low-rate (250 pulse/s) trains. Finally, for relatively short electrode-to-ANF distances, increases in modeled ANF diameter increased the degree of rate adaptation. These results are compared against available feline ANF data, and possible effects of individual parameters are discussed.
Jihwan Woo; Charles A. Miller; Paul J. Abbas. The Dependence of Auditory Nerve Rate Adaptation on Electric Stimulus Parameters, Electrode Position, and Fiber Diameter: A Computer Model Study. Journal of the Association for Research in Otolaryngology 2009, 11, 283 -296.
AMA StyleJihwan Woo, Charles A. Miller, Paul J. Abbas. The Dependence of Auditory Nerve Rate Adaptation on Electric Stimulus Parameters, Electrode Position, and Fiber Diameter: A Computer Model Study. Journal of the Association for Research in Otolaryngology. 2009; 11 (2):283-296.
Chicago/Turabian StyleJihwan Woo; Charles A. Miller; Paul J. Abbas. 2009. "The Dependence of Auditory Nerve Rate Adaptation on Electric Stimulus Parameters, Electrode Position, and Fiber Diameter: A Computer Model Study." Journal of the Association for Research in Otolaryngology 11, no. 2: 283-296.
Recent data from feline auditory nerve fibers (ANFs) indicate that electrically stimulated fibers can undergo large degrees of rate adaptation to pulse-train stimuli using pulse rates within the range used by clinical auditory prostheses. However, the application of Hodgkin-Huxley-type models does not produce such adaptation, which occurs over time periods on the order of 100 ms. We describe our development of a computational ANF axon model that incorporates a time-changing external potassium concentration ([K+]ext) that depends on potassium currents produced by active nodal channel activity. This relatively simple and computationally tractable approach produces poststimulus time histograms that are similar to experimental (cat) data. Furthermore, this mechanism could be easily incorporated into other models to produce much more realistic estimates of the neural coding produced by repeated electric stimulation.
Jihwan Woo; Charles Miller; Paul J. Abbas. Biophysical Model of an Auditory Nerve Fiber With a Novel Adaptation Component. IEEE Transactions on Biomedical Engineering 2009, 56, 2177 -2180.
AMA StyleJihwan Woo, Charles Miller, Paul J. Abbas. Biophysical Model of an Auditory Nerve Fiber With a Novel Adaptation Component. IEEE Transactions on Biomedical Engineering. 2009; 56 (9):2177-2180.
Chicago/Turabian StyleJihwan Woo; Charles Miller; Paul J. Abbas. 2009. "Biophysical Model of an Auditory Nerve Fiber With a Novel Adaptation Component." IEEE Transactions on Biomedical Engineering 56, no. 9: 2177-2180.
When recording single-unit responses from neural systems, a common problem is the accurate detection of spikes (action potentials) in the presence of competing unwanted (noise) signals. While some sources of noise can be readily dealt with through filtering or established "template subtraction" techniques, other sources present a more difficult problem. In particular, noise components introduced by power supplies, which contain harmonics of the power-line frequency, can be particularly troublesome in that they can mimic the shape of the desired spikes. The aforementioned standard techniques typically fail to effectively deal with such "noise". In this study, we propose the use of a novel template-subtraction scheme that involves estimating the power-line noise waveform and using cross-correlation techniques to subtract it from the recordings. This technique requires two key steps: (1) cross-correlation analysis of each recorded waveform to extract a robust representation of the power-line noise waveform and (2) a second level of cross-correlation to successfully subtract that representation from each recorded waveform. This paper describes this algorithm and provides examples of its implementation using actual recorded waveforms that were contaminated with these power-line noise signals. An improvement (reduction) in the noise level is reported, as are suggestions for future implementation of this strategy.
Jihwan Woo; Charles A. Miller; Paul J. Abbas; Sung Hwa Hong; In Young Kim. Improved noise reduction in single fiber auditory neural responses using template subtraction. Journal of Neuroscience Methods 2006, 155, 319 -327.
AMA StyleJihwan Woo, Charles A. Miller, Paul J. Abbas, Sung Hwa Hong, In Young Kim. Improved noise reduction in single fiber auditory neural responses using template subtraction. Journal of Neuroscience Methods. 2006; 155 (2):319-327.
Chicago/Turabian StyleJihwan Woo; Charles A. Miller; Paul J. Abbas; Sung Hwa Hong; In Young Kim. 2006. "Improved noise reduction in single fiber auditory neural responses using template subtraction." Journal of Neuroscience Methods 155, no. 2: 319-327.