Directional hearing aid with variable directivity

Claim 2

In a directional hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm and to create a significant acoustic resistance at the rear portion of the microphone case and thereby effect a phase shift of the sounds entering through such rear portions, a hearing aid housing shaped to fit a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, and a variable acoustic resistance in one of said sound access ports and operable to vary the gains relative to each other produced by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid and thereby change the directivity effect of the hearing aid.

Claim 3

The invention according to claim 1 and the acoustical resistance including a grill in the port, a masking plate lying against the grill and movable along the grill for covering and uncovering portions of the grill to thereby change the acoustical resistance and vary the directivity of the hearing aid.

Claim 4

The invention according to claim 1 and the variable acoustical resistance having a movable part to be moved to vary the acoustical resistance, and said movable part having a control portion accessible from the exterior of the hearing aid housing for moving said part to vary the directivity of the hearing aid.

Claim 5

In a directional hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm and to create a significant acoustic resistance at the rear portion of the microphone case and thereby effect a phase shift of the sounds entering through such rear portions, a hearing aid housing shaped to fit to a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, and a variable acoustic resistance in one of said sound access ports and operable to vary the gains relative to each other produce by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid and thereby change the directivity effect of the hearing aid, the acoustical resistance including a grill in the port, a masking plate lying against the grill and movable along the grill for covering and uncovering portions of the grill to thereby change the acoustical resistance and vary the directivity of the hearing aid, the masking plate being rotatable and having alternate open and closed portions adjacent each other circumferentially of the plate to cover and uncover portions of the grill as the masking plate is rotated to progressively vary the directivity of the hearing aid.

Claim 6

In a directional hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm and to create a significant acoustic resistance at the rear portion of the microphone case and thereby effect a phase shift of the sounds entering through such rear portions, a hearing aid housing shaped to fit to a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, and a variable acoustic resistance in one of said sound access ports and operable to vary the gains relative to each other produce by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid and thereby change the directivity effect of the hearing aid, the acoustical resistance including a grill in the port, a masking plate lying against the grill and movable along the grill for covering and uncovering portions of the grill to thereby change the acoustical resistance and vary the directivity of the hearing aid, the masking plate being rotatable and having alternate open and closed portions adjacent each other circumferentially of the plate to cover and uncover portions of the grill as the masking plate is rotated to progressively vary the directivity of the hearing aid.

Claim 7

The invention according to claim 4 and the rotatable masking plate having a rounded peripheral edge protruding through the housing to the exterior of the housing to facilitate manual rotation of the masking plate to vary the acoustical resistance and directivity of the hearing aid.

Claim 8

The invention according to claim 4 and the grill having adjacent areas, one being partially open and substantially more previous to passage of sound therethrough than the other adjacent area, the closed portion of the masking plate moving across said partly open area of the grill to vary the acoustical resistance and the directivity of the hearing aid.

Claim 9

The invention according to claim 6 and the rotatable masking plate having a circular mounting hub fitting snugly in and rotatable with respect to an opening in the grill, and said rotatable masking plate lying flush against the grill to prevent sound from traveling transversely between the grill and masking plate.

Claim 10

The invention according to claim 5 and the grill and masking plate being disposed at the rear wall portion of the hearing aid housing and in the sound access port thereof to vary the resistance to sounds transmitted through the rear port of the hearing aid and to the microphone.

Claim 11

The invention according to claim 5 and the grill and masking plate being disposed at the front wall portion of the hearing aid housing and in the sound access port thereof to vary the resistance to sounds transmitted through the front port and to the microphone.

Claim 12

In a directional hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm and to create a significant acoustic resistance at the rear portion of the microphone case and thereby effect a phase shift of the sounds entering through such rear portions, a hearing aid housing shaped to fit to a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, and a variable acoustic resistance in one of said sound access ports and operable to vary the gains relative to each other produced by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid and thereby change the directivity effect of the hearing aid, the variable acoustical resistance having a movable part to be moved to vary the acoustical resistance, and said movable part having a control portion accessible from the exterior of the hearing aid housing for moving said part to vary the directivity of the hearing aid, and a second variable acoustical resistance in one of the access ports to the hearing aid housing and having a manually operable control portion disposed wholly within the housing to restrict access thereto.

Claim 13

In a directional hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm and to create a significant acoustic resistance at the rear portion of the microphone case and thereby effect a phase shift of the sounds entering through such rear portions, a hearing aid housing shaped to fit to a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, and a variable acoustic resistance in one of said sound access ports and operable to vary the gains relative to each other produced by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid and thereby change the directivity effect of the hearing aid, the variable acoustical resistance having a movable part to be moved to vary the acoustical resistance, and said movable part having a control portion accessible from the exterior of the hearing aid housing for moving said part to vary the directivity of the hearing aid, and a second variable acoustical resistance in one of the access ports to the hearing aid housing and having a manually operable control portion disposed wholly within the housing to restrict access thereto.

Claim 14

In a hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm, the microphone having an acoustical resistance in the opening at the rear portions of the microphone case to delay the transmission of sounds through the openings in the rear portions of the microphone and thereby induce a directional effect in the microphone, a hearing aid housing shaped to be fit against a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, the openings in the front and rear portions of the microphone case being disposed adjacent to, respectively, the front and rear wall portions of the housing with the front and rear access ports therethrough, means within the housing preventing transmittal of sound from the rear access port of the hearing aid housing to the front soundreceiving opening of the microphone case and also preventing transmittal of sound through the microphone chamber from the front access port and to the sound-receiving openings at the rear of the microphone case, a variable acoustic resistance in the sound access port in the rear wall portion of the hearing aid housing to change the directivity effect of the hearing aid, said variable acoustic resistance including a stationary grill in the rear access port, the grill having adjacent areas of different sound transmitting capabilities, one of said areas having a plurality of closely spaced and minute apertures defining clear passages and cumulatively defining a substantial open area to provide minimum restriction and resistance to passage of sounds therethrough, said individual apertures being sufficiently small as to provide very substantial resistance, acting individually and alone, to passage of sound therethrough, the other of said areas adjacent to the apertured area having substantially less sound transmitting capability than said apertured area, the periphery of the grill being sealed to the hearing aid housisng to prevent any passage of sounds around the edges of the grill and into the microphone chamber, said acoustical resistance also including a rotatable masking plate in the rear sound access port of the hearing aid housing and lying flush against the grill, the periphery of the masking plate being disposed adjacent the periphery of the grill and preventing passage of sounds therebetween, the masking plate having alternate open and closed portions adjacent each other in a direction circumferentially of the plate to cover and uncover portions of the apertured area of the grill, the rotatable masking plate having a rounded edge portion protruding through the hearing aid housing and to the exterior thereof to facilitate manual manipulation of the masking plate which changes the acoustic resistance to sound entering through the rear port of the hearing aid housing to the microphone and change the gains relative to each other produced by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid, thereby changing the directivity effect of the hearing aid.

Claim 15

In a hearing aid, a microphone containing a diaphragm and a transducer and having sound-receiving openings in the front and rear portions of the microphone case to transmit sounds to both sides of the diaphragm, the microphone having an acoustical resistance in the opening at the rear portions of the microphone case to delay the transmission of sounds through the openings in the rear portions of the microphone and thereby induce a directional effect in the microphone, a hearing aid housing shaped to be fit against a person''s head and oriented in a fore and aft direction, the housing having a microphone chamber and front and rear wall portions with sound access ports transmitting sound into the chamber to the microphone, the openings in the front and rear portions of the microphone case being disposed adjacent to, respectively, the front and rear wall portions of the housing with the front and rear access ports therethrough, means within the housing preventing transmittal of sound from the rear access port of the hearing aid housing to the front soundreceiving opening of the microphone case and also preventing transmittal of sound through the microphone chamber from the front access port and to the sound-receiving openings at the rear of the microphone case, a variable acoustic resistance in the sound access port in the rear wall portion of the hearing aid housing to change the directivity effect of the hearing aid, said variable acoustic resistance including a stationary grill in the rear access port, the grill having adjacent areas of different sound transmitting capabilities, one of said areas having a plurality of closely spaced and minute apertures defining clear passages and cumulatively defining a substantial open area to provide minimum restriction and resistance to passage of sounds therethrough, said individual apertures being sufficiently small as to provide very substantial resistance, acting individually and alone, to passage of sound therethrough, the other of said areas adjacent to the apertured area having substantially less sound transmitting capability than said apertured area, the periphery of the grill being sealed to the hearing aid housisng to prevent any passage of sounds around the edges of the grill and into the microphone chamber, said acoustical resistance also including a rotatable masking plate in the rear sound access port of the hearing aid housing and lying flush against the grill, the periphery of the masking plate being disposed adjacent the periphery of the grill and preventing passage of sounds therebetween, the masking plate having alternate open and closed portions adjacent each other in a direction circumferentially of the plate to cover and uncover portions of the apertured area of the grill, the rotatable masking plate having a rounded edge portion protruding through the hearing aid housing and to the exterior thereof to facilitate manual manipulation of the masking plate which changes the acoustic resistance to sound entering through the rear port of the hearing aid housing to the microphone and change the gains relative to each other produced by the hearing aid of sounds originating, respectively, in front of and to the rear of the hearing aid, thereby changing the directivity effect of the hearing aid.

Claim 16

The invention according to claim 11 and the rotatable masking plate having an edge separating the open and closed portions thereof, said edge extending from the central area of the masking plate outwardly toward the edge thereof, and the apertured area of the grill having a boundary edge adjacent the other area of the grill and said boundary edge having an orientation oblique to the edge of the open area of the masking plate whereby to progressively and incrementally close the apertured area of the grill as the masking plate passes thereover.

Claim 17

The invention according to claim 11 and there being a second variable acoustic resistance in the sound access port of the rear wall portions of the housing defining the microphone chamber, said second variable acoustic resistance having a grill with its peripheral edge entirely engaging the housing and preventing passage of sounds into the microphone chamber and around said peripheral edge, the grill of said second acoustic resistance also having a plurality of minute sound transmitting apertures defining clear passages into the microphone chamber and also having an area adjacent said apertures for obstructing passage of sound through the grill of said second resistance, and the second resistance also having a movable masking plate lying flush against the grill and movable to progressively cover and uncover the apertures of the grill of the second sound transmitting resistance, and means confined within the housing for effecting movement of the masking plate of the second acoustic resistance.