Intelligibility of Filtered Synthetic Sentences

1967 ◽  
Vol 10 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Charles Speaks
Keyword(s):  
Low Frequency ◽  
Normal Hearing ◽  
Frequency Filtering ◽  
Frequency Range ◽  
Frequency Bands ◽  
Low Pass ◽  
High Pass

The effects of frequency filtering on intelligibility of synthetic sentences were studied on three normal-hearing listeners. Performance-intensity (P-I) functions were defined for several low-pass and high-pass frequency bands. The data were analyzed to determine the interactions of signal level and frequency range on performance. Intelligibility of synthetic sentences was found to be quite dependent upon low-frequency energy. The important frequency for identification of the materials was approximately 725 Hz. These results are compared with previous findings concerning the intelligibility of single words in quiet and in noise.

A Comparison of the Effects of Filtering and Sensorineural Hearing Loss on Patterns of Consonant Confusions

1978 ◽  
Vol 21 (1) ◽  
pp. 5-36 ◽  
Author(s):  
Marilyn D. Wang ◽  
Charlotte M. Reed ◽  
Robert C. Bilger
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Normal Hearing ◽  
Sensorineural Hearing ◽  
Essentially Normal ◽  
Phonological Features ◽  
Low Pass ◽  
Sequential Information ◽  
The Individual ◽  
High Pass

It has been found that listeners with sensorineural hearing loss who show similar patterns of consonant confusions also tend to have similar audiometric profiles. The present study determined whether normal listeners, presented with filtered speech, would produce consonant confusions similar to those previously reported for the hearing-impaired listener. Consonant confusion matrices were obtained from eight normal-hearing subjects for four sets of CV and VC nonsense syllables presented under six high-pass and six low-pass filtering conditions. Patterns of consonant confusion for each condition were described using phonological features in a sequential information analysis. Severe low-pass filtering produced consonant confusions comparable to those of listeners with high-frequency hearing loss. Severe high-pass filtering gave a result comparable to that of patients with flat or rising audiograms. And, mild filtering resulted in confusion patterns comparable to those of listeners with essentially normal hearing. An explanation in terms of the spectrum, the level of speech, and the configuration of the individual listener’s audiogram is given.

Reverberant Chamber Enhancement

2015 ◽  
Vol 58 (1) ◽  
pp. 24-36
Author(s):  
Daniel Hayes
Keyword(s):  
Fundamental Mode ◽  
Research Laboratory ◽  
Sound Pressure ◽  
Low Frequency ◽  
Naval Research ◽  
Frequency Range ◽  
Testing Frequency ◽  
Acoustic Testing ◽  
High Sound ◽  
High Pass

Typical reverberant chambers used for High Intensity Acoustic Testing (HIAT) can achieve high sound pressure levels (SPL) across most of the applicable frequency range (20 Hz to 10 kHz), but they have limitations. Depending on the size of the chamber, low frequency chamber modes may be limited in the testing frequency range. In addition, reverberant chambers that use conventional 1/3-Octave controllers are not able to control low frequency chamber modes as effectively as the higher frequencies. A typical response to this inability to control the chamber modes is to high pass the frequency range of the excitation in the chamber to prevent exciting the low frequency modes. This method protects the test article from over-testing, although it also might under-test an article that has a fundamental mode below the high-pass frequency of the chamber. Recently, Maryland Sound International conducted a test at the Naval Research Laboratory (NRL) to determine if Direct Field Acoustic Testing (DFAT) technology could be applied to conventional reverberant chambers.

scholarly journals Development of Ultra-Broadband Base Station Antenna for All Mainstream LTE 700/800/900 MHz Frequency Bands

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Doudou Samb ◽  
Zhonglin Wu ◽  
Mulin Liu ◽  
Hu Bin Jie
Keyword(s):  
Development Process ◽  
Low Frequency ◽  
Beam Width ◽  
Base Station ◽  
Frequency Range ◽  
Communication Industry ◽  
Frequency Bands ◽  
Radio Access ◽  
Half Power ◽  
Mobile Communication Industry

LTE deployment is being accelerated due to its improved radio access structure meeting the requirements of current and next generation of wireless networks. Its low band application presents useful aspects such as low density of base station while providing good in-building penetration. In this work, we design and develop a dual-polarized base station antenna supporting 698 MHz to 960 MHz with an azimuth-plan half-power beam width of 90° covering all mainstream LTE 700/800/900 MHz frequency bands representing the widest low frequency range being actively used in the current mobile communication industry. In the design process, rigorous algorithm based on swarm method is developed to tune the electrical performances under strict base station antenna requirements. Experimental results from pattern tests demonstrate the design analysis and the significant advantages of using swarm method in the antenna development process.

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 Low-frequency range magnetic fields at workplaces: hygiene regulation criteria

2021 ◽  
Vol 100 (5) ◽  
pp. 436-443
Author(s):  
Yury P. Paltsev ◽  
Larisa V. Pokhodzey ◽  
Yury V. Kurilenko ◽  
Elena A. Rudneva
Keyword(s):  
Magnetic Fields ◽  
Russian Federation ◽  
Low Frequency ◽  
Frequency Range ◽  
Limit Values ◽  
Frequency Bands ◽  
Target Values ◽  
Scientific Substantiation ◽  
The Russian Federation ◽  
The Impact

Introduction. Until now, in the Russian Federation, unlike Western countries, hygienic regulations have not been developed for magnetic fields (MF) of low-frequency ranges. The aim of the study is a scientific substantiation of the threshold limit values (TLV) of magnetic fields in the range of 3 Hz - 30 kHz at workplaces. Materials and methods. A comparative analysis of domestic and foreign hygienic normative-methodical documentation regulating the TLV of magnetic fields of low-frequency ranges at workplaces is carried out. When substantiating TLV in the frequency range of 3 Hz - 30 kHz, the method of calculating the corrected value of the RMS MF strength in decadal frequency bands is used, taking into account its target values for different exposure times. Results. MF sources in the frequency range 3 Hz - 30 kHz were shown to be widely used in various areas of activity. The analysis of current domestic and foreign documents regulating the impact of MF in low-frequency bands showed the possibility of harmonizing hygienic regulations. The TLV MP in decadal frequency bands and the criteria for their hygienic assessment are scientifically substantiated. Conclusion. The studies made it possible for the first time in the Russian Federation to develop MF hygienic standards in the frequency range of 3Hz - 30 kHz at workplaces, the introduction of which into the practice of sanitary and epidemiological supervision will ensure adequate control over the electromagnetic environment and preservation of workers’ health.

scholarly journals Sound Source Localization by Hearing Preservation Patients with and without Symmetrical Low-Frequency Acoustic Hearing

2015 ◽  
Vol 20 (3) ◽  
pp. 166-171 ◽  
Author(s):  
Louise H. Loiselle ◽  
Michael F. Dorman ◽  
William A. Yost ◽  
René H. Gifford
Keyword(s):  
Source Localization ◽  
Sound Source ◽  
Low Frequency ◽  
Hearing Preservation ◽  
Sound Source Localization ◽  
Localization Accuracy ◽  
Acoustic Hearing ◽  
Low Pass ◽  
Contralateral Ear ◽  
High Pass

The aim of this article was to study sound source localization by cochlear implant (CI) listeners with low-frequency (LF) acoustic hearing in both the operated ear and in the contralateral ear. Eight CI listeners had symmetrical LF acoustic hearing and 4 had asymmetrical LF acoustic hearing. The effects of two variables were assessed: (i) the symmetry of the LF thresholds in the two ears and (ii) the presence/absence of bilateral acoustic amplification. Stimuli consisted of low-pass, high-pass, and wideband noise bursts presented in the frontal horizontal plane. Localization accuracy was 23° of error for the symmetrical listeners and 76° of error for the asymmetrical listeners. The presence of a unilateral CI used in conjunction with bilateral LF acoustic hearing does not impair sound source localization accuracy, but amplification for acoustic hearing can be detrimental to sound source localization accuracy.

Amplitude and Phase in the MüLler-Lyer Illusion

Perception ◽  
10.1068/p2916 ◽  
2000 ◽  
Vol 29 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Bernt C Skottun
Keyword(s):  
Fourier Transform ◽  
Fourier Transforms ◽  
Inverse Fourier Transform ◽  
Low Frequency ◽  
Phase Spectrum ◽  
The Other ◽  
Frequency Filtering ◽  
Lyer Illusion ◽  
Amplitude Spectra ◽  
Low Pass

It has previously been claimed that the Müller-Lyer illusion is the result of low-pass spatial filtering. One way to understand this would be that the distribution of amplitudes is what generates this illusion. This possibility was investigated by computing the 2-D Fourier transforms of the two Müller-Lyer stimuli and extracting their phase and amplitude spectra. These spectra were combined to create hybrid spectra having the phase of one Müller-Lyer figure and the amplitudes of the other. Images were then created by computing the inverse Fourier transform of the hybrid spectra. Except in cases where the analysis was performed patchwise on very small patches, the figures generated with the phase spectrum of the stimuli having outward-pointing fins appear the longer. This was also the case when stimuli were generated with flat amplitude spectra. Because they show that the Müller-Lyer illusion does not depend on any particular distribution of amplitudes, these demonstrations do not support the theory that the Müller-Lyer illusion is the result of low-frequency filtering.

On a Design of Narrowband FIR Low-Pass Filters

2011 ◽  
pp. 2882-2887
Author(s):  
Gordana Jovanovic Dolecek ◽  
Javier Diaz Carmona
Keyword(s):  
Impulse Response ◽  
High Frequency ◽  
Digital Filters ◽  
Stop Band ◽  
Low Frequency ◽  
Pass Band ◽  
Low Pass ◽  
Frequency Components ◽  
Band Pass ◽  
High Pass

Stearns and David (1996) states that “for many diverse applications, information is now most conveniently recorded, transmitted, and stored in digital form, and as a result, digital signal processing (DSP) has become an exceptionally important modern tool.” Typical operation in DSP is digital filtering. Frequency selective digital filter is used to pass desired frequency components in a signal without distortion and to attenuate other frequency components (Smith, 2002; White, 2000). The pass-band is defined as the frequency range allowed to pass through the filter. The frequency band that lies within the filter stop-band is blocked by the filter and therefore eliminated from the output signal. The range of frequencies between the pass-band and the stop-band is called the transition band and for this region no filter specification is given. Digital filters can be characterized either in terms of the frequency response or the impulse response (Diniz, da Silva & Netto, 2002). Depending on its frequency characteristic, a digital filter is either low-pass, high-pass, band-pass, or band-stop filters. A low-pass (LP) filter passes low frequency components to the output, while eliminating high-frequency components. Conversely, the high-pass (HP) filter passes all high-frequency components and rejects all low-frequency components. The band-pass (BP) filter blocks both low- and high-frequency components while passing the intermediate range. The band-stop (BS) filter eliminates the intermediate band of frequencies while passing both low- and high-frequency components. In terms of their impulse responses digital filters are either infinite impulse response (IIR) or finite impulse response (FIR) digital filters. Each of four types of filters (LP, HP, BP, and BS) can be designed as an FIR or an IIR filter (Ifeachor & Jervis, 2001; Mitra, 2005; Oppenheim & Schafer, 1999).

Analysis and Design of a Diplexer for Satellite Communication System

2020 ◽  
Vol 35 (10) ◽  
pp. 1236-1241
Author(s):  
Eman Eldesouki ◽  
Khalid Ibrahim ◽  
Ahmed Attiya
Keyword(s):  
Transmission Lines ◽  
Communication System ◽  
Satellite Communication ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Frequency Bands ◽  
Satellite Communication System ◽  
Analysis And Design ◽  
Low Pass ◽  
High Pass

This paper presents the design and analysis of a diplexer for satellite communication system based on hybrid spoof surface plasmon polariton (SSPP) and substrate integrated waveguide (SIW) transmission lines. The proposed diplexer consists of a SSPP printed line composed of H-shaped periodical grooved strips to operate as a low pass filter and a SIW to operate as a high pass filter. The operating frequency bands of the proposed diplexer are from 11.7 to 12.75 GHz for the downlink (DL) band, and from 17.3 to 18.35 GHz for the uplink (UL) band. These frequency bands correspond to the operating frequencies in Nile Sat 201 system. The frequencies of the DL and UL bands are adjusted independently by tuning the structure parameters of SSPP and SIW sections, respectively. The proposed hybrid SSPP-SIW diplexer is fabricated and measured. Simulated and measured results show good channel isolation, low return loss and low insertion loss in the required frequency bands.

ULTRACOMPACT DIRECTION AND FREQUENCY FILTER CONSISTING OF ALTERNATING METAL LAYERS AND AIR LAYERS

2009 ◽  
Vol 23 (25) ◽  
pp. 2963-2970
Author(s):  
FEI XU ◽  
MING WEI
Keyword(s):  
Low Frequency ◽  
Evanescent Waves ◽  
Structure Parameters ◽  
Frequency Filtering ◽  
Frequency Filter ◽  
Frequency Range ◽  
Transmission Frequency ◽  
Transmission Properties ◽  
Air Layers ◽  
Metal Layers

The transmission properties of a periodic structure consisting of alternating metal layers and air layers are studied by numeric methods. The metal layers are the epsilon-negative (ENG) materials. The interaction of the evanescent waves in metal layers and propagation waves in air layers forms some special transmission bands. Given proper structure parameters, one transmission frequency only allows one incident direction in the low frequency range. This structure can simultaneously achieve frequency filtering and direction filtering.

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