the coal media and increase gas permeability especially near the boreholes increased desorption gas flows result that can be exhausted and sold phased arrays can be used to focus or concentrate the sound energy in such case the radiators are placed within range of each other otherwise they are spaced far apart to lengthen their zone of effect along the drillstring embodiments of the present invention are useful to degasify coal beds with borehole acoustic equipment and inert gases and liquids can more easily and effectively be re injected into coal seams and anomalies to enhance miner health safety and productivity in particular subjecting the near hole area to strong sound waves improves the permeability of the media to natural gas these further include equipment for injecting a second gas into coalbed in order to drive out the desorbing methane the choice of what kind of acoustic radiators 114 121 to use and how to match the radiators with the surrounding media are practical challenges that are overcome by the present invention electrically operated radiators are dangerous because they can spark an explosion of the very gas being extracted connecting them and fitting them with an adequate power source is also problematic not placing the radiators in direct contact with the solid inside faces of the boreholes can result in poor acoustic impedance matching and all the benefits can be lost because strong enough vibrations do not reach the media multiple acoustic radiators 114 117 for example can be mounted on pipe drillstring 108 at critical points and with critical frequency outputs compared to each other so as to produce a phasing of outputs extend or intensify the media zone in which the permeability is increased so the gases or liquids can be removed mechanical sound radiators not powered.