Related Experiment Video
Updated: Jun 4, 2026
08:53
The Measurement of Unsteady Surface Pressure Using a Remote Microphone Probe
Published on: December 3, 2016
Determining the direction to a sound source in air using vector sound-intensity probes
1Sonometrics Inc., 8306 Huntington Road, Huntington Woods, Michigan 48070, USA. hickling.robert@gmail.com
The Journal of the Acoustical Society of America
|February 10, 2011
Summary
This study introduces novel sound intensity probes using four microphones to accurately determine sound source direction. These probes measure the sound intensity vector in 3D or half-space with high precision.
Area of Science:
- Acoustics
- Signal Processing
- Sensor Technology
Background:
- Measuring sound intensity is crucial for source localization and acoustic analysis.
- Traditional methods may require complex setups or a higher number of sensors.
- Omnidirectional probes are essential for accurate sound source direction determination.
Purpose of the Study:
- To develop and validate probes for measuring the vector sound intensity in air.
- To minimize the number of sound pressure sensors required for accurate measurements.
- To enable precise determination of sound source direction using novel probe configurations.
Main Methods:
- Utilizing an arrangement of four small microphones at the vertices of a regular tetrahedron.
- Employing a digital signal processor for sound intensity vector calculation.
- Applying cross-spectral formulation with finite-difference approximations for data processing.
Main Results:
- Demonstrated accurate determination of sound source direction within a few degrees.
- Developed probes capable of measuring the sound intensity vector in both 3D space and half-space.
- Validated the effectiveness of the four-microphone tetrahedral probe design.
Conclusions:
- The developed probes offer a precise and efficient method for measuring vector sound intensity.
- The tetrahedral probe configuration enables accurate sound source localization.
- The technology is applicable to various acoustic environments, including those with reflective surfaces.
Related Concept Videos
00:58Sound Intensity
The loudness of a sound source is related to how energetically the source is vibrating, consequently making the molecules of the propagation medium vibrate. To measure the loudness of a source, the physical quantity of interest is the intensity. This is defined as the energy emitted per unit of time per unit of area perpendicular to the sound wave's propagation direction. Since the total energy is greater if the source vibrates for a longer duration and over a larger area, dividing the emitted...
01:05Intensity and Pressure of Sound Waves
The intensity of sound waves can be related to displacement and pressure amplitudes by using their wave expressions and the definition of intensity. The critical step to achieve this is to write the power delivered by the particles on the wave as the product of force and velocity and simplify the force per unit area as the pressure. The velocity of the medium's particles can be derived from the displacement.
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
Unlike the time average of a sinusoidal term, which is zero since it is positive and...
01:21Perceiving Loudness, Pitch, and Location
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 identifying...
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 identifying...
00:53Sound Intensity Level
Humans perceive sound by hearing. The human ear helps sound waves reach the brain, which then interprets the waves and creates the perception of hearing. The loudness of the environment in which a person is located determines whether they can distinguish between different sound sources.
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
01:01Perception of Sound Waves
The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different frequencies as having different loudness. Moreover, the perception of sound waves depends on the health of an individual's ears, which decays with age. The health of one's ears may also be affected by regular exposure to loud noises.
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
01:16Shock Waves
While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...