now referring to the drawings wherein like numerals refer to like matter throughout , and more specifically to fig1 which is a cutaway exploded view , there is shown an owl hooter game call of the present invention , generally designated 100 . call 100 has a mouth end 102 , for engaging with the mouth of a human call operator and further has an opposing sound exit end 104 , where the sound generated within the call is emitted . call 100 has a reed cover tube 110 , which is shown in a cutaway view revealing the reed assembly 150 disposed therein . reed cover tube 110 has a reed cover tube mouth end 112 and a reed cover tube exit end 114 . call 100 also has an initial sound chamber body 120 , having an initial sound chamber mouth end 122 and an initial sound chamber exit end 124 . initial sound chamber body 120 also has an initial sound chamber thick walled portion 126 and an initial sound chamber thin walled portion 128 with an initial sound chamber boundary edge 127 disposed therebetween . initial sound chamber exit end 124 has an initial sound chamber sound exit hole 129 therein for passage of air therethrough . call 100 further having a back pressure chamber cap 130 with a back pressure chamber cap mouth end 132 and a back pressure chamber cap sound exit end 134 . back pressure chamber cap 130 has a back pressure chamber cap outside surface 136 and a back pressure chamber cap sound exit hole 139 disposed therethrough at said back pressure chamber cap sound exit end 134 . back pressure chamber cap inside surface 137 is visible through back pressure chamber cap sound exit hole 139 . also shown in the cutaway portion of reed cover tube 110 is reed assembly 150 which contains reed assembly body 152 , reed assembly grooved tongue 154 , and reed 156 . all components of the call 100 , except the reed 156 , are preferably made of the same material , which can be any suitable material , including but not limited to birds eye maple and plastic materials . now referring to fig2 there is shown a cross - sectional view of the back pressure chamber cap 130 taken on line 2 — 2 of fig1 . back pressure chamber cap 130 is shown having a back pressure chamber cap outside surface 136 and a back pressure chamber cap inside surface 137 with a back pressure chamber cap sound exit end 134 having a back pressure chamber cap sound exit hole 139 therein . now referring to fig3 as well as fig1 and 2 , when call 100 is fully assembled , initial sound chamber thin walled portion 128 is in contact with back pressure chamber cap inside surface 137 . additionally , back pressure chamber cap mouth end 132 is in contact with initial sound chamber boundary edge 127 . the distance between back pressure chamber cap mouth end 132 and back pressure chamber cap sound exit end 134 is greater than the distance from initial sound chamber boundary edge 127 to initial sound chamber exit end 124 , thereby creating a back pressure sound chamber 140 within back pressure chamber cap 130 . due to the thickness of the walls of initial sound chamber thin walled portion 128 and the fact that back pressure chamber cap outside surface 136 surrounds initial sound chamber thin walled portion 128 , the diameter of back pressure sound chamber 140 is larger than initial sound chamber 142 , which is formed inside initial sound chamber body 120 and between initial sound chamber mouth end 122 and initial sound chamber exit end 124 . in operation , the apparatus of the present invention could function as follows : air is blown into the call 100 at mouth end 102 , the air passes between reed 156 and reed assembly grooved tongue 154 , causing a vibration at a predetermined frequency , the air passes through reed assembly body 152 and enters the initial sound chamber 142 in initial sound chamber body 120 , passes through initial sound chamber sound exit hole 129 in initial sound chamber exit end 124 and then enters back pressure sound chamber 140 formed by the combination of initial sound chamber body 120 and back pressure chamber cap 130 . the dimensions of back pressure sound chamber 140 and initial sound chamber 142 help determine the sound of the call 100 . the precise dimensions throughout the call are a function of many variables which depend on the particular properties that may be desired in a call . it is thought that the apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form , construct steps and arrangement of the parts and steps thereof without departing from the spirit and scope of the invention or sacrificing all of their material advantages . the form herein described is merely a preferred exemplary embodiment thereof .
an owl hooter game call having dual sound chambers arranged in series therein where each sound chamber has a centrally disposed air passage therethrough and one of the sound chambers having a diameter which is larger than the diameter of the other sound chamber .