scholarly journals Selecting Program Material by Audio Features for Low-Frequency Perceptual Evaluation of Loudspeakers

2021 ◽  
Vol 11 (5) ◽  
pp. 2302
Author(s):  
Pei Yu ◽  
Shufeng Zhang ◽  
Xuelei Feng ◽  
Ziyun Liu ◽  
Yong Shen
Keyword(s):  
Predictive Accuracy ◽  
Low Frequency ◽  
Test Results ◽  
Program Material ◽  
Low Frequencies ◽  
Listening Test ◽  
Discrimination Ability ◽  
Perceptual Evaluation ◽  
Audio Features ◽  
Listening Tests

The program material is of great importance for the results of the listening tests on loudspeakers, while the process of how to select the program material remains ambiguous. This paper investigates the criterion for selecting programs suitable for low-frequency perceptual evaluation based on the audio features of the program. A listening test was conducted to identify the more discriminating and revealing programs in the low-frequency range. Based on the listening test results, various characteristics of the programs, including dynamic, timbral, rhythmic, and spectral features, were extracted. Their relationships with the program’s discrimination ability are discussed. The results suggest that programs with a slow and clear rhythm and a smooth and even spectrum in the whole band are more discriminating in detecting the spectral differences in the low frequencies. By using these significant features, a discriminant analysis was performed to predict the ability of the program to reveal the spectral irregularities. The predictive accuracy of the derived discriminant function was 95% in separating the discriminating and undiscriminating programs.

Pendred's Syndrome: A Study of Patients and Relatives

1995 ◽  
Vol 104 (12) ◽  
pp. 957-962 ◽  
Author(s):  
Musa N. Jamal ◽  
Mohammed A. Arnaout ◽  
Ribhi Jarrar
Keyword(s):  
Hearing Loss ◽  
Low Frequency ◽  
Sensorineural Hearing ◽  
The Other ◽  
Test Results ◽  
Profound Hearing Loss ◽  
Low Frequencies ◽  
Pendred’S Syndrome ◽  
Perchlorate Discharge Test ◽  
Discharge Test

Four families, 29 members, with Pendred's syndrome were studied to clarify hearing loss and hormonal status. The ages ranged fro 3 to 50 years. Complete Pendred's syndrome was found in 9 patients. They had bilateral profound hearing loss with residual hearing low frequencies. Goiter was diagnosed at the age of 1 to 14 years with a positive perchlorate discharge test. Twelve of the patient relatives showed partial Pendred's syndrome. Mild sensorineural hearing losses occurred in the low- and medium-range frequencies wi normal perchlorate discharge test results in 6 cases. The other 6 had a slight drop in the perchlorate discharge test results with norm hearing. Five subjects were normal and 3 had normal hormonal and normal perchlorate discharge test results, but were not teste audiologically. This paper shows that patients with Pendred's syndrome may have goiter at birth or develop it between 8 and 14 year that their deafness is bilateral and profound, and that their perchlorate discharge tests are positive. Relatives of Pendred's syndrorr patients showed mild low-frequency sensorineural hearing loss without goiter and normal perchlorate discharge test results in half tl cases, and a slight drop in the perchlorate discharge test results with normal hearing and without goiter in the other half. A correlatic between these findings and genetic studies needs further investigation.

scholarly journals Assessing L2 listening in CALL and listening strategy use

2019 ◽  
Author(s):  
Cristina Pardo-Ballester
Keyword(s):  
Learning Strategies ◽  
Strategy Use ◽  
Strategy Development ◽  
Test Results ◽  
Listening Test ◽  
Listening Tests ◽  
Significant Difference ◽  
L2 Listening ◽  
Instructional Formats ◽  
Video Format

This longitudinal study examines students’ learning strategies of 222 Spanish intermediate learners when taking several listening tests. It also examines the effect of different instructional formats (online-hybrid vs. face2face-blended) on the learners’ strategy use. There were four versions of the same text: an audio format, a video format, a redundancy-enhanced version in audio format, and a redundancy-enhanced version in video format. A pseudo-cross over design was utilized  for this study with four listening tests used with each group. Participants completed a questionnaire immediately after each listening test to learn about learners’ strategies before, during and after listening in order to elicit information about the particular strategies that learners used to complete each listening test. Results indicated that there was a listening comprehension strategy development over time without explicit instruction, but participants from different instructional formats developed different strategies. There was a statistically significant difference for intermediate-low learners when perceiving the use of cognitive and metacognitive strategies, but the effect of redundancy does not seem to have an impact. Intermediate-mid learners did not perceive a difference with the use of strategies when completing listening tests with or without redundancy.

scholarly journals A Perceptual Evaluation of Individual and Non-Individual HRTFs: A Case Study of the SADIE II Database

2018 ◽  
Vol 8 (11) ◽  
pp. 2029 ◽  
Author(s):  
Cal Armstrong ◽  
Lewis Thresh ◽  
Damian Murphy ◽  
Gavin Kearney
Keyword(s):  
Low Frequency ◽  
Test Results ◽  
Spatial Audio ◽  
Frequency Compensation ◽  
Post Processing ◽  
Detailed Understanding ◽  
Perceptual Evaluation ◽  
Measurement And Evaluation ◽  
Processing Techniques

As binaural audio continues to permeate immersive technologies, it is vital to develop a detailed understanding of the perceptual relevance of HRTFs. Previous research has explored the benefit of individual HRTFs with respect to localisation. However, localisation is only one metric with which it is possible to rate spatial audio. This paper evaluates the perceived timbral and spatial characteristics of both individual and non-individual HRTFs and compares the results to overall preference. To that end, the measurement and evaluation of a high-resolution multi-environment binaural Impulse Response database is presented for 20 subjects, including the KU100 and KEMAR binaural mannequins. Post-processing techniques, including low frequency compensation and diffuse field equalisation are discussed in relation to the 8802 unique HRTFs measured for each mannequin and 2818/2114 HRTFs measured for each human. Listening test results indicate that particular HRTF sets are preferred more generally by subjects over their own individual measurements.

Improved Environment-Aware–Based Noise Reduction System for Cochlear Implant Users Based on Knowledge Transfer Approach (Preprint)

2020 ◽  
Author(s):  
Lieber Po-Hung Li ◽  
Ji-Yan Han ◽  
Wei-Zhong Zheng ◽  
Ren-Jie Huang ◽  
Ying-Hui Lai
Keyword(s):  
Knowledge Transfer ◽  
Cochlear Implant ◽  
Noise Reduction ◽  
Speech Intelligibility ◽  
Middle Layer ◽  
Successful Implementation ◽  
Perceptual Evaluation ◽  
Reduction System ◽  
Listening Tests ◽  
Implementation Costs

BACKGROUND The cochlear implant technology is a well-known approach to help deaf patients hear speech again. It can improve speech intelligibility in quiet conditions; however, it still has room for improvement in noisy conditions. More recently, it has been proven that deep learning–based noise reduction (NR), such as noise classification and deep denoising autoencoder (NC+DDAE), can benefit the intelligibility performance of patients with cochlear implants compared to classical noise reduction algorithms. OBJECTIVE Following the successful implementation of the NC+DDAE model in our previous study, this study aimed to (1) propose an advanced noise reduction system using knowledge transfer technology, called NC+DDAE_T, (2) examine the proposed NC+DDAE_T noise reduction system using objective evaluations and subjective listening tests, and (3) investigate which layer substitution of the knowledge transfer technology in the NC+DDAE_T noise reduction system provides the best outcome. METHODS The knowledge transfer technology was adopted to reduce the number of parameters of the NC+DDAE_T compared with the NC+DDAE. We investigated which layer should be substituted using short-time objective intelligibility (STOI) and perceptual evaluation of speech quality (PESQ) scores, as well as t-distributed stochastic neighbor embedding to visualize the features in each model layer. Moreover, we enrolled ten cochlear implant users for listening tests to evaluate the benefits of the newly developed NC+DDAE_T. RESULTS The experimental results showed that substituting the middle layer (ie, the second layer in this study) of the noise-independent DDAE (NI-DDAE) model achieved the best performance gain regarding STOI and PESQ scores. Therefore, the parameters of layer three in the NI-DDAE were chosen to be replaced, thereby establishing the NC+DDAE_T. Both objective and listening test results showed that the proposed NC+DDAE_T noise reduction system achieved similar performances compared with the previous NC+DDAE in several noisy test conditions. However, the proposed NC+DDAE_T only needs a quarter of the number of parameters compared to the NC+DDAE. CONCLUSIONS This study demonstrated that knowledge transfer technology can help to reduce the number of parameters in an NC+DDAE while keeping similar performance rates. This suggests that the proposed NC+DDAE_T model may reduce the implementation costs of this noise reduction system and provide more benefits for cochlear implant users.

scholarly journals Creation of Auditory Augmented Reality Using a Position-Dynamic Binaural Synthesis System—Technical Components, Psychoacoustic Needs, and Perceptual Evaluation

2021 ◽  
Vol 11 (3) ◽  
pp. 1150
Author(s):  
Stephan Werner ◽  
Florian Klein ◽  
Annika Neidhardt ◽  
Ulrike Sloma ◽  
Christian Schneiderwind ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Auditory Perception ◽  
Audio Signal ◽  
Spatial Audio ◽  
Impulse Responses ◽  
Synthesis System ◽  
Perceptual Evaluation ◽  
Listening Tests ◽  
Work Done ◽  
Audio Reproduction

For a spatial audio reproduction in the context of augmented reality, a position-dynamic binaural synthesis system can be used to synthesize the ear signals for a moving listener. The goal is the fusion of the auditory perception of the virtual audio objects with the real listening environment. Such a system has several components, each of which help to enable a plausible auditory simulation. For each possible position of the listener in the room, a set of binaural room impulse responses (BRIRs) congruent with the expected auditory environment is required to avoid room divergence effects. Adequate and efficient approaches are methods to synthesize new BRIRs using very few measurements of the listening room. The required spatial resolution of the BRIR positions can be estimated by spatial auditory perception thresholds. Retrieving and processing the tracking data of the listener’s head-pose and position as well as convolving BRIRs with an audio signal needs to be done in real-time. This contribution presents work done by the authors including several technical components of such a system in detail. It shows how the single components are affected by psychoacoustics. Furthermore, the paper also discusses the perceptive effect by means of listening tests demonstrating the appropriateness of the approaches.

scholarly journals Earless toads sense low frequencies but miss the high notes

2017 ◽  
Vol 284 (1864) ◽  
pp. 20171670 ◽  
Author(s):  
Molly C. Womack ◽  
Jakob Christensen-Dalsgaard ◽  
Luis A. Coloma ◽  
Juan C. Chaparro ◽  
Kim L. Hoke
Keyword(s):  
High Frequency ◽  
Species Differences ◽  
Low Frequency ◽  
Auditory Brainstem ◽  
Low Frequencies ◽  
Hearing Sensitivity ◽  
Sensory Pathways ◽  
Airborne Sound ◽  
Vibrational Sensitivity ◽  
Species Specific

Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. We argue that ancestral bufonids may have sufficient extratympanic hearing and vibrational sensitivity such that earless lineages tolerated the loss of high frequency hearing sensitivity by adopting species-specific behavioural strategies to detect conspecifics, predators and prey.

A waveform inversion technique for measuring elastic wave attenuation in cylindrical bars

Geophysics ◽  
1992 ◽  
Vol 57 (6) ◽  
pp. 854-859 ◽  
Author(s):  
Xiao Ming Tang
Keyword(s):  
Elastic Wave ◽  
Wave Attenuation ◽  
Waveform Inversion ◽  
Finite Size ◽  
Low Frequency ◽  
Frequency Range ◽  
Multiple Reflections ◽  
Low Frequencies ◽  
The Time Domain ◽  
Attenuation Values

A new technique for measuring elastic wave attenuation in the frequency range of 10–150 kHz consists of measuring low‐frequency waveforms using two cylindrical bars of the same material but of different lengths. The attenuation is obtained through two steps. In the first, the waveform measured within the shorter bar is propagated to the length of the longer bar, and the distortion of the waveform due to the dispersion effect of the cylindrical waveguide is compensated. The second step is the inversion for the attenuation or Q of the bar material by minimizing the difference between the waveform propagated from the shorter bar and the waveform measured within the longer bar. The waveform inversion is performed in the time domain, and the waveforms can be appropriately truncated to avoid multiple reflections due to the finite size of the (shorter) sample, allowing attenuation to be measured at long wavelengths or low frequencies. The frequency range in which this technique operates fills the gap between the resonant bar measurement (∼10 kHz) and ultrasonic measurement (∼100–1000 kHz). By using the technique, attenuation values in a PVC (a highly attenuative) material and in Sierra White granite were measured in the frequency range of 40–140 kHz. The obtained attenuation values for the two materials are found to be reliable and consistent.

Methods to isolate retrograde and prograde Rayleigh-wave signals

2019 ◽  
Vol 219 (2) ◽  
pp. 975-994 ◽  
Author(s):  
Gabriel Gribler ◽  
T Dylan Mikesell
Keyword(s):  
Rayleigh Wave ◽  
Time Domain ◽  
Fundamental Mode ◽  
Poisson Ratio ◽  
Low Frequency ◽  
Wave Dispersion ◽  
Low Frequencies ◽  
Retrograde Motion ◽  
Mode Identification ◽  
Time Frequency

SUMMARY Estimating shear wave velocity with depth from Rayleigh-wave dispersion data is limited by the accuracy of fundamental and higher mode identification and characterization. In many cases, the fundamental mode signal propagates exclusively in retrograde motion, while higher modes propagate in prograde motion. It has previously been shown that differences in particle motion can be identified with multicomponent recordings and used to separate prograde from retrograde signals. Here we explore the domain of existence of prograde motion of the fundamental mode, arising from a combination of two conditions: (1) a shallow, high-impedance contrast and (2) a high Poisson ratio material. We present solutions to isolate fundamental and higher mode signals using multicomponent recordings. Previously, a time-domain polarity mute was used with limited success due to the overlap in the time domain of fundamental and higher mode signals at low frequencies. We present several new approaches to overcome this low-frequency obstacle, all of which utilize the different particle motions of retrograde and prograde signals. First, the Hilbert transform is used to phase shift one component by 90° prior to summation or subtraction of the other component. This enhances either retrograde or prograde motion and can increase the mode amplitude. Secondly, we present a new time–frequency domain polarity mute to separate retrograde and prograde signals. We demonstrate these methods with synthetic and field data to highlight the improvements to dispersion images and the resulting dispersion curve extraction.

Fish Attraction with Pulsed Low-Frequency Sound

1968 ◽  
Vol 25 (7) ◽  
pp. 1441-1452 ◽  
Author(s):  
Joseph D. Richard
Keyword(s):  
Acoustic Stimulus ◽  
Low Frequency ◽  
Reef Fishes ◽  
Test Site ◽  
Acoustic Signals ◽  
Commercial Fisheries ◽  
Test Results ◽  
Potential Applications ◽  
Predatory Fishes ◽  
Underwater Television

A series of tests were conducted to determine the effectiveness of pulsed low-frequency acoustic signals for attracting fishes. The acoustic signals were contrived to simulate the hydrodynamically generated disturbances normally associated with active predation. Underwater television was used to observe fish arrivals during both control and test periods. Demersal predatory fishes were successfully attracted although they habituated rapidly to the acoustic stimulus. Members of the families Serranidae, Lutjanidae, and Pomadasyidae were particularly well represented among the fishes attracted. Sharks were also attracted in considerable numbers. Herbivorous reef fishes, although common around the test site, were not attracted. Possible relationships between the test results and the hearing capabilities of fishes are discussed. It is concluded that acoustic attraction techniques have potential applications in certain existing commercial fisheries.

Shock Test and Acceleration Analysis Methods of Marine Diesel Engines to Underwater Explosions

2013 ◽  
Vol 345 ◽  
pp. 64-67
Author(s):  
Jian Hua Zhao ◽  
Rui Bo Zhang ◽  
De Bin Zhu ◽  
Hong Bin Gao
Keyword(s):  
Diesel Engine ◽  
Low Frequency ◽  
Vibration Signal ◽  
Test Methods ◽  
Shock Acceleration ◽  
Test Results ◽  
Shock Test ◽  
Marine Diesel ◽  
Reduction Methods ◽  
Acceleration Analysis

Shock test of marine diesel engine is the important content for ship anti-shock research. Plentiful shock tests of equipments have been carried out abroad, but there is no detailed test methods of diesel engine. According to simulation results, 8-channel acceleration test points are determined. Because diesel engine is working, the measured shock acceleration is interfered by vibration signal. Orthogonal wavelet decomposition and wavelet noise reduction methods are used to separate shock component from test results. The seperated shock component consists of two parts. One is the low-frequency part caused by the shock from diesel foundation and then attenuation through the isolator, the other is the high-frequency part caused by the secondary shock of the retainer.

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