Related Experiment Video
Updated: Oct 7, 2025
04:32
Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention
Published on: December 20, 2024
504
A Noise Control Method Using Adaptive Adjustable Parametric Array Loudspeaker to Eliminate Environmental Noise in
1Key Laboratory for Optoelectronic Technology and System of the Education Ministry of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China.
International Journal of Environmental Research and Public Health
|January 11, 2022
Summary
Environmental noise poses health risks, necessitating effective noise control. This study introduces an adjustable parametric array loudspeaker (PAL) for real-time noise elimination, offering improved control and reduced feedback compared to traditional methods.
Area of Science:
- Acoustics
- Environmental Science
- Signal Processing
Background:
- Long-term exposure to environmental noise negatively impacts human health.
- Traditional noise control methods using voice coil loudspeakers (VCLs) face limitations due to sound omni-directionality, causing increased sound pressure in non-target areas and acoustic feedback.
- Effective noise suppression is crucial for public health and creating quiet environments.
Purpose of the Study:
- To propose and evaluate an online secondary path modeling method for real-time environmental noise elimination.
- To investigate the use of an adjustable parametric array loudspeaker (PAL) as a secondary source for noise control.
- To assess the performance of PAL in terms of noise reduction, propagation distance, acoustic feedback, and quiet area distribution.
Main Methods:
- Developed an online secondary path modeling method utilizing an adjustable parametric array loudspeaker (PAL).
- Employed ultrasound-based technology for noise elimination.
- Adaptively adjusted PAL size based on target distance for long-distance noise control.
- Analyzed the distribution of generated quiet areas.
Main Results:
- The PAL demonstrated comparable noise reduction effects to traditional VCLs.
- The PAL exhibited longer sound propagation distance and significantly reduced acoustic feedback.
- The study achieved a more regular and controllable distribution of quiet areas.
- Adaptive adjustment of PAL size enabled effective noise control for targets at varying distances.
Conclusions:
- An adjustable parametric array loudspeaker (PAL) offers an effective alternative to traditional voice coil loudspeakers (VCLs) for environmental noise control.
- PAL technology provides enhanced control over noise reduction, with benefits including extended propagation distance and minimized acoustic feedback.
- This research holds significant potential for improving environmental quality and establishing quieter living spaces.
Related Concept Videos
01:21Perceiving Loudness, Pitch, and Location
492
The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception.
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by...
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by...
492
01:17Design Example: Vintage Mixing Console
321
A sound engineer at a music company recently encountered a problem. The output from their newly acquired studio's vintage mixing console was too low for the requirements of modern recording equipment. To rectify this situation, the engineer decided to design an audio pre-amplifier using an operational amplifier (op-amp) to boost the signal level.
The specifications for the pre-amplifier were clear. It needed to amplify the audio signal by a factor of 10, have an input impedance above 10...
The specifications for the pre-amplifier were clear. It needed to amplify the audio signal by a factor of 10, have an input impedance above 10...
321
01:23Design Example
396
The innovation of touch-tone telephony revolutionized the telecommunications industry by replacing the traditional rotary dial with a dual-tone multi-frequency (DTMF) signaling system. This system uses a matrix-style keypad with buttons arranged in four rows and three columns, creating 12 distinct signals each assigned to a pair of frequencies. Each button press results in a simultaneous generation of two sinusoidal tones – one from a low-frequency group (697 to 941 Hz) and one from a...
396
01:25Active Filters
961
Active filters are electronic circuits that use operational amplifiers (op-amps), resistors, and capacitors to filter out unwanted frequency components from a signal. A first-order low-pass active filter is designed to pass signals with a frequency lower than a certain cutoff frequency and attenuate frequencies higher than that cutoff frequency. The transfer function for a first-order low-pass active filter is:
961
01:26Feedback control systems
473
Feedback control systems are categorized in various ways based on their design, analysis, and signal types.
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
473