Then transmitting an acoustical frequency acoustical signal into the wall of the hole.

For example, an alternate voice frequency (112) using the same antenna as the reference frequency may be chosen.

In an acoustooptic tunable filter embodiment, polarization coupling results from a surface acoustic wave and tuning is accomplished by changing the acoustic frequency.

The use of the strong modular isolators provides acoustic isolation between the transmitters and receivers for the complete sonic frequency band at multiple modes.

A determination is then made as to whether the antenna used for the reference frequency is the same as that used by the selected voice frequency (66, 104).

A first of the plurality of acoustic transceivers operates at a first acoustic frequency and is operatively connected to a first group of transducers producing an acoustic signal.

A second of the plurality of acoustic transceivers operates at a second acoustic frequency and is operatively connected to a second group of transducers producing an acoustic signal.

Sound and acoustic Frequencies have been Tour validated to inspire confidence and enhance feel.

Drive signal producing means involves phase-shifting higher acoustic frequency content, and is further operative for in-phase action of at least some of the transducers in sub-area(s) of the array for lower frequency content.

It causes an acoustic frequency and also they call it Voice to Skull.

They generate tones of a predefined volume and frequency.

Various metals can be used, as well as various parameters as to temperature, pressure, acoustic energy (12), acoustic frequency, and composition of the reactants, which may be employed to vary the results.

David: And that creates an acoustic frequency that people can hear?

A sensor for detecting acoustic energy includes a microstructure tuned to a predetermined acoustic frequency and a device for detecting movement of the microstructure.

Apart from the acoustic frequency response in dBSPL (left), the impedance frequency response (right) may also be interesting.