Introduction to Underwater panoramic sound

Since 3 dimensional spatial property of waves can be measured by a 4-point measurement, a full-spherical panoramic sound in air can be recorded with a tetrahedral microphone system that consists of 4 microphones.

If the microphones are replaced by hydrophones, panoramic sound can be recorded in the water.

Since the sound speed is much faster in water than in air, it has to be adjusted programmatically. Other than that, panoramic sound in water can be recorded and reproduced by almost the same procedure as that in air.

Recording system

Figure 1 is a picture of a tetrahedral hydrophone system with a full-spherical video camera. The system has 4 hydrophones.

A photo of the system placed in water is shown in Fig. 2.


Fig.1 Tetrahedral hydrophone system with a full-spherical camera
An underwater panoramic sound recording system consists of 4 omnidirectional hydrophones. The full-spherical video camera (RICOH THETA SC) is in the waterproof case.


Fig.2 Tetrahedral hydrophone system in water
Each hydrophone (AQUARIAN AUDIO H2a-XLR) is at the vertex of a tetrahedron.

Please see the video introducing the tetrahedral hydrophone system. Stereo headphones are necessary
promotional video ->

A full-spherical panoramic video is also available. Stereo headphones are necessary

Hydro_demo.sopa

More demonstrations

Sounds in the following video clips were recorded in the water. Please use stereo headphones to listen to the sounds.

By clicking one of the thumbnails below, you can start the demo. Once the image is loaded and the page says "Click to start" or "Tap to start," you can start reproducing the sound by clicking (tapping) on the image.


Submariner.sopa
Squal.sopa
Turtle.sopa

Applications


Fig.3 Applications of underwater panoramic sound