# US 11,115,752 B2 · Sound transducer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,752 B2 - Document ID: US11115752B2 - Status: Granted - Kind: B2 - Application number: 16/754,542 - Filed: 2017-10-11 - Published: 2020-08-27 - Granted: 2021-09-07 - Earliest claimed: 2017-10-11 - Assignees: Institut Fur Rundfunktechnik GmbH - Applicants: Institut FüR Rundfunktechnik - Inventors: Roman Stumpner - Web page: https://patentgrep.com/patent/US11115752B2 ## CPC - H04R 1/2869: {Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself} - H04R 1/1091: {Details not provided for in groups H04R1/1008 - H04R1/1083} - H04R 5/033: Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)} - H04S 7/30: {Control circuits for electronic adaptation of the sound field} - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H04S: STEREOPHONIC SYSTEMS ## Abstract According to the present invention, an apparatus, a signal processing unit, data, a processing apparatus, a sound converter, a software product and a method are proposed. The apparatus is proposed for acoustic reproduction, wherein the apparatus is provided with a first electroacoustic sound transducer for generating a sound field, the first electroacoustic sound transducer having an input for receiving an electrical signal for generating the corresponding sound field, wherein the apparatus is characterized in that also a device is provided which is configured to enter into an acoustic interaction with the generated sound field of the first electroacoustic sound transducer in order to generate a modified sound field and wherein the modified sound field has a predetermined acoustic impedance value. ## Claims ### Claim 1 An apparatus for acoustic reproduction comprising: a first electroacoustic sound transducer for generating a sound field, the first electroacoustic sound transducer comprising an input for receiving an electrical signal for generating the sound field; and a device configured to enter into an acoustic interaction with the generated sound field of the first electroacoustic sound transducer in order to generate a modified sound field, the device comprising one of: at least one acoustic resonator; and at least one further electroacoustic sound transducer, wherein the modified sound field has a predetermined acoustic impedance value, the device being configured to receive impedance information and to convert the impedance information into an acoustic signal so that a modified acoustic field has a predetermined acoustic impedance value through a corresponding acoustic interaction. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the at least one acoustic resonator comprises one of: a recess resonator and a Helmholtz resonator, the at least one acoustic resonator configured at a housing of the apparatus. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein at least one of the first electroacoustic sound transducer, the at least one further electroacoustic sound transducer, and/or the at least one acoustic resonator are controllable in order to set different acoustic impedance values in the modified sound field. ### Claim 4 (depends on 1) The apparatus of claim 1 further comprising: a measuring unit, in particular a microphone for measuring a sound field parameter in order to be able to derive a given impedance value in the sound field therefrom, to enable generation of a subsequent electrical adaptation signal. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein the apparatus is designed as at least one of: headphones; and/or earphones. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein a position and/or an orientation of at least one of the first electroacoustic sound transducer, the at least one further electroacoustic sound transducer, and/or of the at least one acoustic resonator is designed to be changeable. ### Claim 7 A signal processing unit for acoustic reproduction, the signal processing unit being configured to: process an acoustic interaction with a first sound field, based on a first electroacoustic sound transducer and a second electroacoustic sound transducer, provided for generating the first sound field; generate a modified sound field, wherein the modified sound field has a predetermined acoustic impedance value; measure a current impedance value in the first sound field with a control loop in order to implement subsequent readjustment of the modified sound field; and process further relevant acoustic parameters, in particular geometric parameters of a headphone or an earphone, in order to set the predetermined acoustic impedance value for the modified sound field. ### Claim 8 (depends on 7) The signal processing unit according to claim 7, the signal processing unit being further configured to: provide a factor based on at least one sound pressure and/or one sound velocity to generate a modified sound field, wherein the modified sound field has a predetermined acoustic impedance value. ### Claim 9 (depends on 8) The signal processing unit according to claim 8 further comprising: at least one microphone, configured to measure the sound pressure and the sound velocity. ### Claim 10 (depends on 7) The signal processing unit according to claim 7 further comprising: a sound transducer wherein the signal processing unit is configured to process an impedance signal provided by the sound transducer. ### Claim 11 (depends on 7) The signal processing unit according to claim 7, wherein the modified sound field has a temporally predetermined variable acoustic impedance value. ### Claim 12 (depends on 7) The signal processing unit according to claim 7 wherein the signal processing unit comprises at least one of: a smartphone; a notebook; a laptop; a tablet PC; a personal computer; a wireless transmitter; and/or a server. ### Claim 13 A method for acoustic reproduction, the method comprising: generating a first sound field with a first electroacoustic sound transducer; generating a second signal for acoustic interaction with the first sound field; generating a modified sound field from the acoustic interaction between the second signal and the first sound field, wherein the modified sound field has a predetermined acoustic impedance value; receiving impedance information; and converting the impedance information into an acoustic signal so that the modified sound field has the predetermined acoustic impedance value. ### Claim 14 (depends on 13) The method of claim 13 further comprising: setting different acoustic impedance values in the modified sound field. ### Claim 15 (depends on 13) The method of claim 13 further comprising: measuring a sound field parameter with a microphone; and deriving a given impedance value therefrom. ### Claim 16 (depends on 15) The method of claim 15 further comprising: generating a subsequent electrical adaptation signal according to the sound field parameter and the derived given impedance value.