Acoustic characterisation of thoracic body tissues in the audible frequency range

1995 ◽  
Vol 21 (2) ◽  
pp. 113-124 ◽  
Author(s):  
M. P. Jones ◽  
D. W. Thomas
Keyword(s):  
Frequency Range ◽  
Body Tissues ◽  
Audible Frequency

scholarly journals Student Sensor Lab at Home: Safe Repurposing of Your Gadgets

2020 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
Alexander N. Kalashnikov ◽  
Ali Elyounsi ◽  
Alan Holloway
Keyword(s):  
Learning Experience ◽  
Electronic Devices ◽  
Frequency Range ◽  
High Quality ◽  
Potential Harm ◽  
Electronic Circuitry ◽  
Conventional Teaching ◽  
Audible Frequency ◽  
Periodic Safety ◽  
At Home

The COVID-19 pandemic imposed various restrictions on the accessibility of conventional teaching laboratories. Enabling learning and experimenting at home became necessary to support the practical element of students’ learning. Unfortunately, it is not viable to provide or share a fully featured sensor lab to every student because of the prohibitive costs involved. Therefore, repurposing electronic devices that are common to students can bring about the sought-after practical learning experience without the hefty price tag. In distinction to the conventional lab instruments, however, consumer-grade devices are not designed for use with external sensors and/or electronic circuitry. They are not professionally maintained, do not undergo periodic safety tests, and are not calibrated. Nevertheless, nearly all modern computers, laptops, tablets or smartphones are equipped with high-quality audio inputs and outputs that can generate and record signals in the audible frequency range (20 Hz–20 kHz). Despite cutting off the direct currents completely, this range might be sufficient for working with a variety of sensors. In this presentation we look at the possibilities of making sure that such repurposing by design prevents any potential harm to the learner and to her or his personal equipment. These features seem essential for unsupervised lone experimenting and avoiding damage to expensive devices.

A New Analyzer for the Audible Frequency Range

1933 ◽  
Vol 5 (1) ◽  
pp. 62-62 ◽  
Author(s):  
H. H. Hall ◽  
D. G. Clifford
Keyword(s):  
Frequency Range ◽  
Audible Frequency

scholarly journals Measurement of Earmuffs Attenuation at High Audible Frequencies

2017 ◽  
Vol 42 (2) ◽  
pp. 249-254
Author(s):  
Emil Kozłowski ◽  
Rafał Młyński
Keyword(s):  
Frequency Band ◽  
Measurement Method ◽  
Sound Attenuation ◽  
The Other ◽  
Hearing Protection ◽  
Noise Attenuation ◽  
Frequency Range ◽  
Test Fixture ◽  
Hearing Protectors ◽  
Audible Frequency

Abstract Standardised measurements of sound attenuation of hearing protectors are performed in the frequency range from 125 Hz to 8 kHz. However, noise present at many workplaces contains significant components at higher audible frequency. Therefore, the knowledge about noise attenuation with earmuffs in the audible frequency range above 8 kHz is also necessary for proper hearing protection. The aim of this study was to obtain values of the noise attenuation with 27 commonly-used earmuffs models in the 1/3 octave bands of 10, 12.5 and 16 kHz. The measurements were conducted with a real ear at threshold (REAT) method with participation of subjects. The study showed that attenuation of earmuffs ranged from 24.7 to 42.8 dB, depending on model of earmuffs and frequency band. Furthermore, the measurements were performed with the use of acoustic test fixture which is designed especially for testing hearing protectors. Results obtained with the use of acoustic test fixture indicated that this measurement method can lead to values close to attenuation measured with participation of subjects. On the other hand, values obtained with the use of acoustic test fixture may differ average up to 14 dB from REAT method.

scholarly journals MODELING OF HUMAN BODY TISSUES IMPEDANCE COMPONENTS IN FREQUENCY RANGE

2019 ◽  
Vol 80 (4) ◽  
pp. 49-53
Author(s):  
Olena Naumovych ◽  
◽  
Yevhen Pokhodylo ◽  
Marta Dovhan ◽  
◽  
...  
Keyword(s):  
Human Body ◽  
Frequency Range ◽  
Body Tissues
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