A method for feeding pressurized air pulses to a quarter wave resonance tube, for generating a standing low-frequency sound wave in said quarter wave resonance tube. The method entails that the pressurized air pulses supply maximum input power to said standing low-frequency sound wave by feeding said pressurized air pulses only during the time intervals of the oscillation cycle when the air pressure in said rear end of the quarter wave resonance tube, is positive. Also disclosed is a revolving valve, for feeding pressurized air pulses to a quarter wave resonance tube, for generating a standing low-frequency sound wave in said quarter wave resonance tube.

A method for feeding pressurized air pulses to a quarter wave resonance tube, for generating a standing low-frequency sound wave in said quarter wave resonance tube. The method entails that the pressurized air pulses supply maximum input power to said standing low-frequency sound wave by feeding said pressurized air pulses only during the time intervals of the oscillation cycle when the air pressure in said rear end of the quarter wave resonance tube, is positive. Also disclosed is a revolving valve, for feeding pressurized air pulses to a quarter wave resonance tube, for generating a standing low-frequency sound wave in said quarter wave resonance tube.

An apparatus for metering the delivery of a fluid. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region.

An apparatus for metering the delivery of a fluid. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region.

An apparatus for metering the delivery of an aerosol. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region. An atomizer, coupled to the fluid region, is configured to aerosolize at least a portion of the fluid.

An apparatus for metering the delivery of an aerosol. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region. An atomizer, coupled to the fluid region, is configured to aerosolize at least a portion of the fluid.

An apparatus includes a marine seismic source having a volume of gas and a gas reservoir, and the marine seismic source and the gas reservoir are coupled to permit a resonating gas flow to pass therebetween. The apparatus may be a component of a marine seismic survey system. The apparatus may be utilized in a method of marine seismic surveying.

An apparatus includes a marine seismic source having a volume of gas and a gas reservoir, and the marine seismic source and the gas reservoir are coupled to permit a resonating gas flow to pass therebetween. The apparatus may be a component of a marine seismic survey system. The apparatus may be utilized in a method of marine seismic surveying.

Horn systems having a first bracket, a second bracket, a compressor and a horn are described. The horns may have a sound unit and a bell with tubing connecting the compressor and the sound unit. The tapered neck of the horn's bell may be secured by the second bracket surrounding the tapered neck and fixing it in position when the second bracket is secured relative to the first bracket.

Horn systems having a first bracket, a second bracket, a compressor and a horn are described. The horns may have a sound unit and a bell with tubing connecting the compressor and the sound unit. The tapered neck of the horn's bell may be secured by the second bracket surrounding the tapered neck and fixing it in position when the second bracket is secured relative to the first bracket.