reference will now be made in detail to the preferred embodiments of the invention , examples of which are illustrated in the accompanying drawings . the invention may , however , be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein ; rather , these embodiments are provided so that this disclosure will be thorough and complete , and will fully convey the concept of the invention to those skilled in the art . in the drawings , the thicknesses of layers and regions are exaggerated for clarity . like reference numerals in the drawings denote like elements . fig1 is a perspective view of headphones with portions removed to expose an internal energy storage device according to an exemplary embodiment of the invention . as shown in fig1 , the headphones 100 can include a headband 110 , a left housing 120 , a right housing 130 , and an internal energy storage device 140 . both the left housing 120 and the right housing 130 can include an acoustic transducer 132 and can include a comfort padding 134 which surrounds the user &# 39 ; s ear . one of the left housing 120 or the right housing 130 can include an on / off switch 124 , an on / off indicator 122 , a receiver 126 , and a power input ( not shown ). the headband 110 can be connected to the left housing 120 and the right housing 130 . the energy storage device 140 can be mounted inside the headband 110 . various electronic components ( not shown ) in the left housing 120 or the right housing 130 can be electrically connected to the internal energy storage device 140 . the left housing 120 or the right housing 130 can be connected to an on / off switch 124 , an on / off indicator 122 , a receiver 126 , an acoustic transducer 132 , and comfort padding 134 . the acoustic transducer 132 , on / off switch 124 , on / off indicator 122 , and receiver 126 can be electrically connected to the internal energy storage device 140 . the left housing 120 and right housing 130 can come in a variety of sizes and shapes ( not shown ), including basic geometric shapes like ovals , squares , circles , to conform with a user &# 39 ; s preferences , style , and fit . the on / off switch 124 can be a button and the receiver 126 can be wired or wireless . the headphones can include other electronic controls ( not shown ) such as a volume control buttons / wheel , and buttons to connect to applicable wireless frequencies . these other electronic controls can be fitted onto the left housing 120 or right housing 130 . in this way , the headphones can be configured in a multitude of ways to appeal to a mass consumer market while providing consumers pricing options . the headphone &# 39 ; s 100 headband 110 may come in variety of types , including circumaural , sport ( not shown ), and supra - aural ( not shown ). circumaural headphones can have a headband 110 that rests on the top of the user &# 39 ; s head where the acoustic transducers 132 in the left housing 120 and right housing 130 are separated from a users ear by the comfort padding . sport headphones can include a headband that rests on the back of the user &# 39 ; s head where the occipital bone is located . supra - aural headphones can include acoustic transducers 132 in the left housing 120 and the right housing 130 that are directly pressed against the user &# 39 ; s ears because the headband 110 acts as a flat spring . in the instance of circumaural headphones , the headband 110 can be substantially u - shaped , square shaped , or elliptical shaped . depending on the shape of the headband 110 , the comfort padding 134 can be placed on the inner circumference of the left housing 120 and right housing 130 adjacent a user &# 39 ; s head . the comfort padding 134 can provide both comfort to the user and can attenuate external noise . the acoustic transducer &# 39 ; s 132 can come in a multitude of options such as loud speakers , moving - coil drivers , electrostatic transducers , and bone conduction transducers . the energy storage device 140 mounted on the headband 110 may be of a flexible or solid consistency . the shape of the energy storage device can be can be straight or curved . the decision of whether the energy storage device is flexible or curved can depend of a number of factors , including a necessity to conform to the headband shape or consumer pricing . in embodiments of the invention , the energy storage device 140 can be mounted such that the center of gravity is located in approximately the center of the headband 110 . the energy storage device 140 can be mounted such that the mass of the energy storage device 140 is equally distributed on both sides of a midpoint ( not shown ) of the headband 110 . the mass of the energy storage device 140 on a left side of headband 110 can be approximately equal to the mass of the energy storage device mounted on the right side of the headband 110 . the energy storage device 140 can be formed from a multitude of different electrochemical cells which are well known in the art such as nickel - cadmium , nickel - metal hydride , lithium - ion , lithium - ion polymer , lithium sulfur , and potassium - ion . the electrochemical cells can be rechargeable via an external power source . an energy storage device 140 can be flexible and can be comprised of single or multiple thin film rechargeable lithium batteries . the headband 110 can be formed from plastic such as polypropylene , polystyrene , high impact polystyrene , polyvinyl chloride , high - density polyethylene , low - density polyethylene , polyamides , acrylonitrile butadiene styrene , polycarbonate , or polycarbonate / acrylonitrile butadiene styrene blend . the headband 110 can be formed of metal such as aluminum , alloys of aluminum , copper , alloys of copper , alloys of iron , alloys of nickel , alloys of titanium , alloys of tin , and alloys of zinc . the headband 110 can include leather , artificial leather , rubber , textiles , foam materials , silicone , vinyl , and other advanced plastics . the comfort padding 134 can be formed of silicone , foam materials such as memory foam , rubber , polyurethane , bonded urethane , hydrogels , xerogels , and other textiles . the comfort padding 134 can be lined with leather , artificial leather , rubber , vinyl , advanced plastics , and other natural and artificial textiles . fig2 is a perspective view of headphones with portions removed to expose a plurality of internal energy storage devices according to an exemplary embodiment of the invention . as shown in fig1 , the headphones 200 can include a headband 210 , a left housing 220 , a right housing 230 , and multiple internal energy storage devices 240 . both the left housing 220 and the right housing 230 include an acoustic transducer 232 and can include a comfort padding 234 that can surround a user &# 39 ; s ear . one of the left housing 220 or the right housing 230 can further include an on / off switch 224 , an on / off indicator 222 , a receiver 226 , an display 225 , and a power input ( not shown ). the headband 210 can be connected to the left housing 220 and the right housing 230 . the multiple energy storage devices 240 can be mounted on the headband 210 . the multiple energy storage devices 240 can be electrically interconnected . various electrical components ( not shown ) in the left housing 220 or the right housing 230 can be electrically connected to the multiple energy storage devices 240 . the left housing 220 or the right housing 230 can be physically connected to the on / off switch 224 , on / off indicator 222 , receiver 226 , acoustic transducer 232 , and comfort padding 234 . the acoustic transducer 232 , on / off switch 224 , on / off indicator 222 , and receiver 226 can be electrically connected to the internal energy storage device . the multiple energy storage devices 240 on the headband 210 can be flexible or solid . the shape of the energy storage devices can be straight or curved to conform to the shape of the headband 210 . the energy storage devices can be electrically connected , such as in parallel or series , to provide the electrical power to the transducers 232 and receiver 226 and other electrical components ( not shown ) such as amplifier or noise cancellation processor . to maintain the center of gravity and equilibrium of the headphones 200 , the mass of the energy storage devices 240 placed on the left side of headband 210 can be approximately equal to the mass of the energy storage devices placed on the right side of the headband 210 . the energy storage devices can be include different electrochemical cells such as nickel - cadmium , nickel - metal hydride , lithium - ion , lithium - ion polymer , and potassium - ion . the display 225 can be a touch screen lcd screen . the display 225 can interface with the receiver 226 to receive information from an audio transmitting device such as laptop computer or portable music player . the receiver 226 can be a bluetooth receiver that receives song and track information from a laptop or portable music player and display relevant information on the screen 225 . in embodiments where the screen 225 is a touch screen , the screen 225 can further receive inputs from a user which are transmitted via bluetooth to an audio transmitting device to control the audio transmitting device . the inputs can be , among other things , instructions to change tracks , increase or decrease the volume , play , pause , or stop the music . in the retail environment , the left housing 220 and right housing 230 can come in a variety of sizes and shapes ( not shown ), including basic geometric shapes like ovals , squares , circles , to conform with a user &# 39 ; s preferences , style , and fit . the on / off switch 224 can be a button and the receiver 226 can be wired or wireless . the headphones can include other electronic controls ( not shown ), such as a volume control buttons / wheel , and buttons to connect to applicable wireless frequencies . these other electronic controls can be fitted onto the left housing 220 or right housing 230 . in this manner , the headphones can be configured in a multitude of ways to appeal to a mass consumer market while providing consumers various pricing options . the headphone &# 39 ; s 200 headband 210 can come in variety of types , including circumaural , sport ( not shown ), and supra - aural ( not shown ). in the instance of circumaural headphones , the headband 210 can be substantially u - shaped , square shaped , or elliptical shaped . depending on the variety of the headphone 200 , a comfort padding 234 can be placed on the inner circumference of the left housing 220 and right housing 230 adjacent the user &# 39 ; s head ; the comfort padding 234 can provide both comfort to the user and can attenuate external noise . the acoustic transducers 232 can come in a multitude of options such as loud speakers , moving - coil drivers , electrostatic transducers , and bone conduction transducers . the energy storage devices 240 mounted on the headband 210 can be flexible or solid . the energy storage devices 240 can be straight or curved to conform to the headband shape or consumer pricing . to maintain the center of gravity and an approximately equal distributed mass of the energy storage devices 240 mounted on the headphones 200 , the masses of the energy storage devices mounted on the left side of headband 210 can be approximately equal to the masses of the energy storage device mounted on the right side of the headband 210 . fig3 a - 3b are sectional perspective views of a headband with an energy storage device mounted on a headband according to an exemplary embodiment of the invention . as shown in fig3 a - 3b , the headband 310 includes a top layer 312 , a left side wall 314 , a right side wall 316 , and a bottom layer 318 . the culmination of the layers in the headband can provide sufficient space to mount multiple energy storage devices 320 or a single energy storage device 330 . the energy storage device 320 or 330 can be straight or curved to match the curvature of the headband 310 . the thickness of the headband 310 may vary depending on the style of headphones , the width of the energy storage device , and the required energy to power the receiver and acoustic transducers supplied in the headphones . the headband 310 can be constructed in a multitude of manners thereby allowing variation in the styles and configuration thereof . the headband 310 can be one solid band as pictured , but can be split into two or more independent bands within the curvature , and at a congruent point on the opposite end of the curvature , merge into one solid band again . as such , the headband 310 can include sufficient space between the top layer 312 , left side wall 313 , right side wall 316 , and bottom layer 318 to allow a single energy storage device 330 or multiple energy storage devices 320 to be mounted therein . the headband 310 can include a left side wall 314 , a right side wall 316 , and a bottom layer 318 in which the energy storage devices 320 or energy storage device 330 can be mounted . the energy storage device 330 or energy storage devices 320 can be exposed and form the top layer of the headband 310 . the exposure of the energy storage device 330 or energy storage devices 320 can be used in instances when the power input ( not shown ) includes photovoltaic cells mounted onto the energy storage device ( s ), where the photovoltaic cells can be substituted for the top layer 312 . the energy storage device ( s ) can include a thin film flexible rechargeable battery combined with photovoltaic cells which can act as the top layer 312 , the energy storage device 330 or energy storage devices 320 , and power input ( not shown ). such a combination can result in a headband 310 that has an energy source fueled using solar power and other external sources . fig4 a - 4b are side views of headphones according to an exemplary embodiment of the invention . as shown in fig4 a , the headphones 400 include a headband 410 , a left housing 420 including an acoustic transducer , a right housing 430 including an acoustic transducer , and multiple electronically connected energy storage devices 440 mounted on the headband 410 . the energy storage devices 440 mounted in the head band 410 can be distributed such that the mass of the energy storage devices on the left side of the headband 410 is approximately equal to the mass of the energy storage devices 440 on the right side of the headband 410 . one of the left housing 420 or right housing 430 can include a receiver 424 or a power port 422 for charging the energy storage devices 440 . the headband 410 can be connected to the left housing 420 , the right housing 430 , the adjustable band 450 , and multiple energy storage devices 440 . the left housing 420 and the right housing 430 can be connected to the adjustable band 450 . the multiple energy storage devices 440 can be electronically interconnected . the multiple energy storage devices 440 can be electronically connected to the various electrical components ( not shown ) in the left housing 420 and the right housing 430 such as the power port 422 and the receiver 424 . the left housing 420 and right housing 430 can include additional energy storage devices 460 a and 460 b , respectively . as shown in fig4 b , the headphones 400 include a headband 410 , a left housing 420 including an acoustic transducer , a right housing 430 including an acoustic transducer , an energy storage device 440 can be mounted on the headband 410 such that the mass of the energy storage device 440 on the left side of the headband 410 is approximately equal to the mass of the energy storage device 440 on the right side of the headband 410 . one of the left housing 420 or right housing 430 can include a receiver 424 and an power plug 422 for charging the energy storage device 440 . the headband 410 can be connected to the left housing 420 , the right housing 430 , an adjustable band 450 , and an energy storage device 440 . the left housing 420 and the right housing 430 can be connected to the adjustable band 450 . the energy storage device 440 can be electronically connected to the various electrical components ( not shown ) in the left housing 420 and right housing 430 . for user comfort and ease of use , the headband 410 can include an adjustable band 450 that connects the headband 410 to the left housing 420 and right housing 430 . the adjustable band 450 can allow the left housing 420 or the right housing 430 to slide vertically to and from the headband 410 . the adjustable band 450 can allow the left housing 420 and right housing 430 to be centered over a user &# 39 ; s ears regardless of the size of the user &# 39 ; s head . fig5 a - 5c are sectional perspective views of a housing for an acoustic transducer . as shown in fig5 a , a housing for an acoustic transducer 510 can be attached to a substantially u - shaped headband 500 via an adjustable headband 530 . the housing 510 can include an on / off indicator 512 , an on / off switch 514 , and a receiver 516 . the housing can include an energy storage device 520 . additional energy storage devices ( not shown ) can be mounted in the headband 500 . the energy storage device 520 can be electronically connected to an on / off indicator 512 , an on / off switch 514 , a receiver 516 , and other energy storage devices ( not shown ). the adjustable band 530 can be mounted to the housing for an acoustic transducer 510 and the headband 500 . the adjustable band 530 can be slidably attached to the housing 510 such that the housing 510 can slide vertically to and from the headband 500 so as to be adjustable to match the size of a user &# 39 ; s head . as shown in fig5 b , the substantially u - shaped headband 500 can be connected to a housing for an acoustic transducer 510 by a mounted adjustable band 530 . the housings 510 can be located at opposite ends of the headband 500 . the housing for an acoustic transducer 510 can include an on / off indicator 512 , an on / off switch 514 , a receiver 516 , and a power input port 518 . the adjustable band 530 can be exposed when the housing 510 is pulled away from the headband 500 or when the headband 500 is pulled away from the housing 510 . this feature can provide an additional length to the headband 500 so as to conform to a user &# 39 ; s head size . a housing 510 can contain power input port 518 which can receive external power to provide energy into the energy storage devices ( not shown ) mounted within the headband 500 . the power input port 518 can be electronically connected to an energy storage device mounted within the headband 500 ( not shown ) or within the housing 510 . the power input port 518 can be located on various locations on the headband 500 or housing 510 to accommodate to various styles of headphones . the power input port 518 can accept multiple types of power plugs such as a dc coaxial plug , usb plug , or a standard ac plug . electrical power from an external source ( not shown ) can interface with the headphones via the power input port 518 . the power input port 518 can be electrically connected to an energy storage device ( s ) ( not shown ) that are mounted within the headband 500 or the housing 510 . the headphones can include a photovoltaic module ( not shown ) which generates electrical power from ambient light and can be used to charge the energy storage device ( s ) ( not shown ). as shown in fig5 c , a housing for an acoustic transducer 510 includes an on / off indicator 512 , an on / off switch 514 , a receiver 516 , a power input port 518 , and an audio input port 519 . a u - shaped headband 500 can be connected to the housing for an acoustic transducer 510 . the housing for an acoustic transducer 510 can be connected to an adjustable band ( not shown ). the adjustable band ( not shown ) can retract back into the headband 500 when a user pushes the housing for an acoustic transducer 510 towards the headband , and as such , is concealed when a user pushes the housing 510 . the housing 510 can include an audio input port 518 that can receive an analog audio signal via a traditional wire such as an ⅛ ″ audio plug . the receiver 516 can receive a wireless audio signal via bluetooth or other suitable wireless audio transmission protocol . fig6 a - 6b are exemplary electrical schematics for an energy storage device and acoustic transducers . as shown in fig6 a , an energy storage device 600 can include be formed from single or multiple cells which are electrically interconnected in parallel . the number of cells in the energy storage device 600 can be sufficient to provide adequate electrical power to the acoustic transducers 630 , receiver ( not shown ), and other electronic components contained within the headphones . the energy storage device 600 can be electrically connected to an on / off switch 622 , an on / off indicator 624 , and acoustic transducers 630 . the energy storage device 600 can be electrically connected to the power input port 620 for providing electrical power to recharge the energy storage device 600 . power from the energy storage device 600 can flow to the acoustic transducers 630 when the user activates the on / off switch 622 . upon activating the on / off switch 622 , the circuit can close and the on / off indicator 624 can provide a visible signal that power is being supplied to the headphones . the indicator 624 can be an led indicator and can provide a visible signal that the headphones are receiving electrical power . upon de - activation of the on / off switch 622 , the circuit can open and the on / off indicator 624 can indicate that power is not being provided to the acoustic transducers 630 . as shown in fig6 b , an energy storage device 610 can include single or multiple cells connected in series . the number of cells in the energy storage device 610 can be sufficient to provide adequate electrical power to the acoustic transducers 630 , receiver ( not shown ), or other electrical components ( not shown ) in the headphones . the energy storage device 610 can be electrically connected to an on / off switch 622 , and on / off indicator 624 , and acoustic transducers 630 . the energy storage device 610 can be electronically connected to a power input port 620 which can provide electrical power for recharging the energy storage device 610 . power from the energy storage device 610 flows to the acoustic transducers 630 when the user activates the on / off switch 622 . upon activating the on / off switch 622 , the circuit closes and the on / off indicator 624 provides a visible signal that the headphones are on . upon de - activation of the on / off switch 622 , the circuit opens which causes the on / off indicator 624 to no longer provide a signal to the user and no power is provided to the acoustic transducers 630 . although the present invention has been described in considerable detail with reference to certain preferred embodiments , other embodiments which do not vary from the sprit or scope of this invention are contemplated . therefore , the appended claims should not be limited to the description of the preferred embodiments contained herein . it will be apparent to those skilled in the art that various modifications and variations can be made to the headphones having a distributed mass power source without departing from the spirit or scope of the invention . thus , it is intended that embodiments of the invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents .