Acoustic velocity microphone using a buoyant object

A method for determining a particle velocity of an acoustic wave, the method comprising:

• suspending a buoyant object with a feature size that is smaller than a wavelength of the highest frequency of an acoustic wave in air in a sensor frame structure using a support means,
• detecting three-dimensional movement that the buoyant object receives from the air excited by the acoustic wave using a detection means;
• and
• deriving a particle velocity of the acoustic wave from the three-dimensional movement of the buoyant object using the detection means.

A method for determining an acoustic image of an acoustic wave, the method comprising:

• distributing two or more directional acoustic sensors in a multi-dimensional array, wherein each directional acoustic sensor of the two or more directional acoustic sensors includes a sensor frame structure, a support means, and a buoyant object suspended in the sensor frame structure using a support means that has a feature size smaller than a wavelength of the highest frequency of an acoustic wave in air and that receives three-dimensional movement of the air excited by the acoustic wave;
• detecting three-dimensional movement of each directional acoustic sensor of the two or more directional acoustic sensors using a detection means;
• deriving a particle velocity of the acoustic wave from the three-dimensional movement of each buoyant object of each directional acoustic sensor of the two or more directional acoustic sensors producing a plurality of particle velocities of the acoustic wave using the detection means;
• and
• calculating an acoustic image of the acoustic wave from the a plurality of particle velocities and known locations of the multi-dimensional array using a processor.