Patent ID: 8919493

Claim:
A composition comprising a frequency adjustor and a switch; wherein the frequency adjustor comprises a porous body, where the porous body has interstitial spaces and an average porosity between 100 and 500 microns, a proximal end and a distal end, wherein the frequency adjustor alters at least a portion of the frequency of sound produced by exhaled gas from a diving regulator, wherein the frequency of sound produced by the bubbles exiting the frequency adjustor into surrounding fluid through the porous body has a frequency that approximates the background noise of the fluid into which the bubbles are introduced; and, wherein the proximal end is in fluid communication with a second stage scuba regulator; and, wherein the switch has at least an open and a closed position and is coupled to the distal end of the porous body such that when the switch is in the open position a substantial portion of the exhaled gas exits the frequency adjustor at the distal end without going through the porous body, and when the switch is in a closed position a substantial portion of the exhaled gas exits the frequency adjustor by going through the porous body and wherein the exhalation effort that is experienced by a human user during exhalation of the gas through a portion of the porous body is not less than 2.5 inches of water.