Speech recognition as a function of high-pass filter cutoff frequency for people with and without low-frequency cochlear dead regions

2007 ◽  
Vol 122 (1) ◽  
pp. 542-553 ◽  
Author(s):  
Vinay ◽  
Brian C. J. Moore
Keyword(s):  
Speech Recognition ◽  
Cutoff Frequency ◽  
Low Frequency ◽  
Pass Filter ◽  
High Pass Filter ◽  
Cochlear Dead Regions ◽  
High Pass

scholarly journals A Compact High-Pass Filter Using Hybrid Microstrip/Nonuniform CPW with Dual-Mode Resonant Response

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Hui Chen ◽  
Di Jiang ◽  
Ke-Song Chen ◽  
Hong-Fei Zhao
Keyword(s):  
Printed Circuit Board ◽  
Coplanar Waveguide ◽  
Cutoff Frequency ◽  
Circuit Board ◽  
Dual Mode ◽  
Pass Filter ◽  
High Pass Filter ◽  
Mode Characteristic ◽  
High Pass ◽  
Good Agreement

A novel and miniature high-pass filter (HPF) based on a hybrid-coupled microstrip/nonuniform coplanar waveguide (CPW) resonator is proposed in this article, in which the designed CPW has exhibited a wideband dual-mode characteristic within the desired high-pass frequency range. The implemented filter consists of the top microstrip coupled patches and the bottom modified nonuniformly short-circuited CPW resonator. Simulated results from the electromagnetic (EM) analysis software and measured results from a vector network analyzer (VNA) show a good agreement. A designed and fabricated prototype filter having a 3 dB cutoff frequency (fc) of 5.78 GHz has shown an ultrawide high-pass behavior, which exhibits the highest passband frequency exceeding 4.0fcunder the minimum insertion loss (IL) 0.75 dB. The printed circuit board (PCB) area of the filter is approximately0.062λg×0.093λg, whereλgis the guided wavelength atfc.

Construction of a High-Pass Digital Filter from a Low-Pass Digital Filter

1994 ◽  
Vol 10 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Stephen D. Murphy ◽  
D. Gordon E. Robertson
Keyword(s):  
Digital Filter ◽  
Low Frequency ◽  
Frequency Noise ◽  
Band Pass Filter ◽  
Low Frequency Noise ◽  
Pass Filter ◽  
Low Pass Filter ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

To remove low-frequency noise from data such as DC-bias from electromyo-grams (EMGs) or drift from force transducers, a high-pass filter was constructed from a low-pass filter of known characteristics. A summary of the necessary steps required to transform the low-pass digital were developed. Contaminated EMG and force platform data were used to test the filter. The high-pass filter successfully removed the low-frequency noise from the EMG signals. The high-pass filter was then cascaded with the low-pass filter to produce a band-pass filter to enable simultaneous high- and low-frequency noise reduction.

scholarly journals Application of Butterworth high pass filter as an approximation of Wood Anderson seismometer frequency response to earthquake signal recording

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 379
Author(s):  
Hamidatul Husna Matondang ◽  
Endra Joelianto ◽  
Sri Widiyantoro
Keyword(s):  
Frequency Response ◽  
Signal To Noise Ratio ◽  
Cutoff Frequency ◽  
Maximum Amplitude ◽  
Second Order ◽  
Pass Filter ◽  
High Pass Filter ◽  
Local Earthquake ◽  
Seismic Magnitude ◽  
High Pass

The method for generating maximum amplitude and signal to noise ratio values by using second order high pass Butterworth filter on local seismic magnitude scale calculations is proposed. The test data are signals from local earthquake that have been occurred in Sunda Strait on April 8th 2012. Based on the experimental results, a 8 Hz cutoff frequency and a gain of 2200 of second order Butterworth high pass filter as an approach to simulating the frequency response of Wood Anderson seismometer can provide maximum amplitude value, SNR, and the magnitude better than simulated Wood Anderson frequency response.

scholarly journals Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

2016 ◽  
Vol 120 (5) ◽  
pp. 552-563 ◽  
Author(s):  
Jonathan D. Smirl ◽  
Keegan Hoffman ◽  
Yu-Chieh Tzeng ◽  
Alex Hansen ◽  
Philip N. Ainslie
Keyword(s):  
Blood Pressure ◽  
Lower Body Negative Pressure ◽  
Function Analysis ◽  
Low Frequency ◽  
Moderate Intensity ◽  
Pass Filter ◽  
High Pass Filter ◽  
Age Related ◽  
Transfer Function Analysis ◽  
High Pass

The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (<0.20 Hz) and faster oscillations are passed through relatively unimpeded. During moderate intensity exercise, previous studies have reported paradoxical transfer function analysis (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20–30 yr; n = 10) and older (62–72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45–50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02–0.07 Hz) and low frequency (0.07–0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (−34%) in phase (−0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels.

Notizen: A Contribution to the Stark-Spectroscopy at Low Microwave Frequencies

1979 ◽  
Vol 34 (7) ◽  
pp. 903-905 ◽  
Author(s):  
W. Schrepp ◽  
H. Dreizler
Keyword(s):  
Double Resonance ◽  
Low Frequency ◽  
Frequency Region ◽  
Absorption Cell ◽  
Stark Spectroscopy ◽  
Pass Filter ◽  
Square Wave ◽  
High Pass Filter ◽  
High Pass ◽  
Lower Frequencies

Recently we published a construction of a micro­wave-microwave double resonance spectrometer [1], which allows a variety of experiments. An essential part of it is a “stripline” absorption cell.Although Stark-Spectroscopy [2] gave a very important impetus to the investigation of rotation spectra and is in use for three decades, measure­ments below 6.5 GHz are few in number compared to the frequency region above 6.5 GHz.The reason is that generally the line intensity decreases at lower frequencies and the cross sections of the standard waveguides are larger. If one does not use special waveguides * a higher Stark voltage has to be applied to produce the necessary Stark field for modulation. This requires a rather powerful Stark square wave generator** to load and unload the capacity of the absorption cell.Measurements in the low frequency region may be useful since at these lower frequencies the density of rotational spectra is sometimes considerably lower than at higher frequencies, which faciliates the assignement.We noticed that the stripline cell, which transmits from DC to 18 GHz in a coaxial type mode, may be used for Stark-Spektroscopy by feeding the Stark voltage and the microwave simultaneously to the septum. After having finished our experiments, we noticed that S. Weisbaum [4] et al. measured the transitions 32 - 3a and 52 - 53 of HDO at 486.50 and 824.64 MHz, respectively, by a similar tech­nique. The radiofrequency was connected together with the Stark voltage to the septum of a conven­tional Stark cell.In Fig. 1 we give the details of the set up. To combine the microwave and the square wave we use “monitor tees” *. The square wave is fed into the monitor port which transmits a 100 kHz square wave. For example, a residual square wave of 140 V is observed at the microwave port when applying a 400 V square wave. To prevent any influence of the square wave on the microwave sourcje we use a piece of waveguide as a high pass filter. At the output of the absorption cell another piece af waveguide acting as a high pass filter protects the detector cristal. The cell we used for the measurements presented in Table 1 and Fig. 2 is made of an X-band waveguide R100 (cut off for the TE10-mode 6.56GHz). The construction is similar to that given in Fig. 1 of the previous paper [1], but TNC connectors** are used. The cell has been tested for a voltage of 2500 V between septum and the waveguide walls. The attenuation of the microwave on the stripline between 0.4 and 2.4 GHz is about 1.5 dB.

Analog and Digital Filtering of the Brain Stem Auditory Evoked Response

1989 ◽  
Vol 98 (7) ◽  
pp. 508-514 ◽  
Author(s):  
Kevin T. Kavanagh ◽  
Renaee Franks
Keyword(s):  
Phase Shift ◽  
Wave Amplitude ◽  
Cutoff Frequency ◽  
Evoked Response ◽  
Auditory Evoked Potential ◽  
Pass Filter ◽  
Auditory Evoked Response ◽  
High Pass Filter ◽  
High Pass ◽  
Zero Phase

This study compared the filtering effects on the auditory evoked potential of zero and standard phase shift digital filters (the former was a mathematical approximation of a standard Butterworth filter). Conventional filters were found to decrease the height of the evoked response in the majority of waveforms compared to zero phase shift filters. a 36-dB/octave zero phase shift high pass filter with a cutoff frequency of 100 Hz produced a 16% reduction in wave amplitude compared to the unfiltered control. a 36-dB/octave, 100-Hz standard phase shift high pass filter produced a 41% reduction, and a 12-dB/octave, 150-Hz standard phase shift high pass filter produced a 38% reduction in wave amplitude compared to the unfiltered control. a decrease in the mean along with an increase in the variability of wave IV/V latency was also noted with conventional compared to zero phase shift filters. The increase in the variability of the latency measurement was due to the difficulty in waveform identification caused by the phase shift distortion of the conventional filter along with the variable decrease in wave latency caused by phase shifting responses with different spectral content. Our results indicated that a zero phase shift high pass filter of 100 Hz was the most desirable filter studied for the mitigation of spontaneous brain activity and random muscle artifact.

Pulse-shape distortion introduced by broadband deconvolution

1992 ◽  
Vol 82 (1) ◽  
pp. 238-258
Author(s):  
Stuart A. Sipkin ◽  
Arthur L. Lerner-Lam
Keyword(s):  
Transfer Function ◽  
Ground Motion ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequencies ◽  
Pass Filter ◽  
Long Period ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

Abstract The availability of broadband digitally recorded seismic data has led to an increasing number of studies using data from which the instrument transfer function has been deconvolved. In most studies, it is assumed that raw ground motion is the quantity that remains after deconvolution. After deconvolving the instrument transfer function, however, seismograms are usually high-pass filtered to remove low-frequency noise caused by very long-period signals outside the frequency band of interest or instabilities in the instrument response at low frequencies. In some cases, data must also be low-pass filtered to remove high-frequency noise from various sources. Both of these operations are usually performed using either zero-phase (acausal) or minimum-phase (causal) filters. Use of these filters can lead to either bias or increased uncertainty in the results, especially when taking integral measures of the displacement pulse. We present a deconvolution method, based on Backus-Gilbert inverse theory, that regularizes the time-domain deconvolution problem and thus mitigates any low-frequency instabilities. We apply a roughening constraint that minimizes the long-period components of the deconvolved signal along with the misfit to the data, emphasizing the higher frequencies at the expense of low frequencies. Thus, the operator acts like a high-pass filter but is controlled by a trade-off parameter that depends on the ratio of the model variance to the residual variance, rather than an ad hoc selection of a filter corner frequency. The resulting deconvolved signal retains a higher fidelity to the original ground motion than that obtained using a postprocess high-pass filter and eliminates much of the bias introduced by such a filter. A smoothing operator can also be introduced that effectively applies a low-pass filter. This smoothing is useful in the presence of blue noise, or if inferences about source complexity are to be made from the roughness of the deconvolved signal.

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