What is acoustic holography?
Acoustic holography is a process in which sound waves are recorded and arranged in a visual pattern using a computer. The audio field can be modeled to reconstruct its structure using three -dimensional (3D) images. The sound fields that radiate from the surface of musical instruments, aircraft, submarines and automotive interiors are measured to study how the design affects the spread of sound. Two basic types are acoustic holography in the nearby field and remotely. The computer processes this data for the reconstruction of the sound field in the visual format. Time data is associated with specific frequencies to create a representative set of holograms that are divided into waves based on their distribution characteristics. The sound source is calculated by means of an inverse calculation, so the field can be danked by every sound wave.
Acoustic holography of a nearby field is used to locate sound from a relatively close source. More microphones are arranged in rectangular configuration, placed horizontallyand vertically. Half wavelengths of maximum and minimum frequencies are measured, which depend on the spacing of microphones and field size. Sound intensity calculations are possible from the measured sound source, but the propagation of waves can only be assessed in parallel with the measured surface. The technique of acoustic holography is also limited to testing high -frequency sounds.
Processing technique called focal focalization of the nearby field is formed by rays that produce spherical sound waves around the microphones. Spatial resolution of measurement improves if it is equal to the level of focalization or is at higher frequency. The 3D holography of the nearby field can be combined with other simulation techniques on the computer and with the relevant focal can be used to measure low-premium frequency sounds.
In acoustic holography remotely, the hologram is generated by data collected far from the source. The resolution is limited to the half -wave length measurement. ThisThe restrictions can only be compensated by measuring sound from a closer range.
Acoustic holography involves measuring sound pressure. It can explain various acoustic references, surfaces known to vibrate at certain frequencies and different properties of the sound signal. Data can also be obtained from different locations, for example in the vehicle and be connected together using the data collection software to create an even larger image to analyze the sound wave.