CN102655628B - Device and method for detecting high sound pressure-phase shifting characteristic of microphone - Google Patents
Device and method for detecting high sound pressure-phase shifting characteristic of microphone Download PDFInfo
- Publication number
- CN102655628B CN102655628B CN201210044550.4A CN201210044550A CN102655628B CN 102655628 B CN102655628 B CN 102655628B CN 201210044550 A CN201210044550 A CN 201210044550A CN 102655628 B CN102655628 B CN 102655628B
- Authority
- CN
- China
- Prior art keywords
- microphone
- sound pressure
- phase
- end cap
- variable cross
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
- Circuit For Audible Band Transducer (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention provides a device and a method for detecting a high sound pressure-phase shifting characteristic of a microphone. A variable-section closed space is formed by an equal-phase coupling cavity, a variable-section reflection end cover, a standing wave tube and a bottom reflection end cover; a loudspeaker in the standing wave tube is connected with a power amplifier; the power amplifier is connected with a signal source; the signal source is connected with a computer; a reference microphone and a calibrated microphone are respectively arranged on the side wall of the equal-phase coupling cavity and are connected with a signal amplifier; and the signal amplifier is connected with the computer. The method comprises the following steps of: controlling the signal source by the computer, and driving the loudspeaker in the standing wave tube to send a sound wave signal by the power amplifier; and performing cross-spectrum analysis on a signal which is acquired by the reference microphone and the calibrated microphone, so as to obtain a phase difference of the calibrated microphone relative to the reference sensor under a certain condition. A sound source has high sound pressure of 94 to 160 decibels according to a standing wave sound field theory, and the distortion degree is less than 1 percent; and therefore, the phase shifting characteristic of the phase sensitivity of the microphone is calibrated under a high sound pressure environment.
Description
Technical field
The present invention relates to acoustic metrology technical field, be specifically related to a kind of checkout gear and method of microphone high sound pressure-phase-shift characterisitc.
Background technology
Microphone claims again " acoustic-electrical transducer ", is transducer crucial in acoustical testing, is the converting means that acoustical signal in air is converted to the signal of telecommunication, and its sensitivity has phase characteristic, is commonly called phse sensitivity.In recent years along with modern acoustics measuring technology development, there is acoustical holography analysis, sounding target localization, sounding accident analysis, the sound new technologies such as coupling analysis of shaking, these technology all need to use the phse sensitivity of microphone, be mainly used in noise source positioning analysis, remote acoustic target identification, engine noise failure diagnosis, the acoustical testing work such as rocket launching on-the-spot test, the sound pressure level of these test environments has covered the dynamic range to 165dB from 80dB, and microphone there will be nonlinear phase offset characteristic under high sound pressure level (more than 140dB) environment, the microphone phase error of introducing is the main source that affects measurement result accuracy.
For the microphone phase error of introducing, existing collimation technique adopts pressure field coupling cavity relative phase calibration steps, can under the environment of 124dB sound pressure level, calibrate microphone phse sensitivity, and calibration structure principle as shown in Figure 1.Signal source 3 is exported a fixed frequency (250Hz) normal signal, at the pressure field sound pressure signal of interior this frequency of generation of active coupling cavity 2, the bulk of active coupling cavity 2 requires to be less than 1/20 of wavelength, the sound pressure level producing is no more than 124dB, proofing microphone 1 and standard microphone 4 are installed in active coupling cavity 2 two ends, make these two microphones the amplitude equiphase sound pressure signal such as experience, be transformed to the signal of telecommunication by measuring amplifier 7, data acquisition card 6 is converted to digital data transmission by analog electrical signal A/D and processes to computer 5, computer 5 calculates the phase difference of two path signal by Cross Spectra Analysis, can calculate the phase difference of tested microphone relative standard microphone under this frequency.But, under high sound pressure level (more than 140dB) environment, then adopt in this way phase alignment, can produce a difficult problem for microphone phse sensitivity nonlinear phase shift, cannot realize microphone phase alignment.
Summary of the invention
The present invention is for solving the calibration problem of microphone phse sensitivity nonlinear phase shift under high sound pressure level (more than 140dB) environment, a kind of checkout gear and method of microphone high sound pressure-phase-shift characterisitc are proposed, it uses standing-wave sound field principle to make sound source reach the high sound pressure of 160dB, and distortion factor < 1%, can realize the phase-shift characterisitc calibration of microphone phse sensitivity under high sound pressure environment by equiphase coupling cavity.
Realize the technical scheme of the object of the invention: a kind of checkout gear of microphone high sound pressure-phase-shift characterisitc, it comprises an equiphase coupling cavity that falls " U " shape, equiphase coupling cavity is fixedly connected on variable cross-section reflection end the cover side of center with through hole; The through hole internal diameter of the internal diameter of equiphase coupling cavity and variable cross-section reflection end cap equates, and the external diameter of equiphase coupling cavity is less than variable cross-section and reflects the external diameter of end cap; The top of standing wave tube is fixedly connected on variable cross-section reflection end cap below, and the bottom of standing wave tube is fixedly connected on bottom reflection end cap; The internal diameter of standing wave tube is greater than the through hole internal diameter of variable cross-section reflection end cap, and the external diameter of standing wave tube equals the external diameter of variable cross-section reflection end cap; Form a variable cross-section confined space by equiphase coupling cavity, variable cross-section reflection end cap, standing wave tube, bottom reflection end cap;
In standing wave tube, above bottom reflection end cap, be provided with loud speaker; Loud speaker connects power amplifier by lead-out wire, and power amplifier is connecting signal source also, and signal source connects computer again; Wherein, connection power amplifier in computer control signal source drives loud speaker to send normal acoustic signals; The normal acoustic signals that loud speaker sends multiple reflections in above-mentioned variable cross-section confined space forms high sound pressure stationary field;
In the two side of equiphase coupling cavity, symmetric position place opens mouth, is arranged on respectively passage port with reference to microphone and proofing microphone; Also be connected signal amplifier by lead-out wire respectively with reference to microphone with proofing microphone, signal amplifier connects computer again; Wherein, with reference to the sound pressure amplitude in microphone monitoring equiphase coupling cavity, by signal amplifier, real-time sound pressure amplitude is passed to computer, then by the sound pressure amplitude in computer control signal source and then control equiphase coupling cavity; Can obtain microphone high sound pressure-phase-shift characterisitc by witness mark microphone from the phase difference of proofing microphone under different sound pressure levels.
The checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc as above, the external diameter of the equiphase coupling cavity described in it is 1/2～1/3 times of external diameter of variable cross-section reflection end cap; The internal diameter of described standing wave tube is 2～3 times of through hole internal diameter of variable cross-section reflection end cap.
The checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc as above, the normal acoustic signals that loud speaker described in it sends multiple reflections in variable cross-section confined space forms high sound pressure stationary field, in this stationary field, sound pressure level can reach 94～160dB, sound wave distortion factor < 1%.
The detection method of a kind of microphone high sound pressure-phase-shift characterisitc of the present invention, it comprises the steps:
(a) by the sinusoidal signal of computer control signal source output setpoint frequency f, sound pressure amplitude P0, then drive the loud speaker in standing wave tube to send acoustic signals by power amplifier;
(b) loud speaker in step (a) sends acoustic signals multiple reflections in variable cross-section confined space, form stable state stationary field, sound pressure amplitude and the phase place experienced with reference to microphone and proofing microphone are all equated, and sound pressure level reaches 94～160dB, distortion factor < 1%;
(c) collect the sound pressure amplitude P0 in equiphase coupling cavity with reference to microphone, by signal amplifier, real-time sound pressure signal is converted to electrical signal transfer to computer, these data of computer real-time analysis, and adjust the output amplitude of signal source, make the stable set point P0 that remains on of sound pressure amplitude in equiphase coupling cavity, form close loop control circuit;
(d) signal collecting with reference to microphone and proofing microphone carries out Cross Spectra Analysis and obtains: the phase difference of proofing microphone relative reference microphone under frequency f, sound pressure amplitude P0 condition, obtains microphone high sound pressure-phase-shift characterisitc.
The detection method of a kind of microphone high sound pressure-phase-shift characterisitc as above, the setpoint frequency f described in it is that 500～800Hz, sound pressure amplitude P0 are 1～2000Pa.
Effect of the present invention is: the checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc of the present invention and method, can realize the FEEDBACK CONTROL of sound pressure level in equiphase coupling cavity, can there is upper limit 160dB, the sound pressure signal of lower limit 94dB, and distortion factor < 1%; Can solve the calibration problem of sensitivity of microphone nonlinear phase shift under high sound pressure level (more than 140dB) environment.
Brief description of the drawings
Fig. 1 is for adopting pressure field coupling cavity relative phase calibration steps;
Fig. 2 is the structure of the detecting device schematic diagram of a kind of microphone high sound pressure-phase-shift characterisitc of the present invention;
In figure: 1. proofing microphone; 2. active coupling cavity; 3. signal source; 4. standard microphone; 5. computer; 6. data acquisition card; 7. measuring amplifier; 8. with reference to microphone; 9. equiphase coupling cavity; 10. variable cross-section reflection end cap; 11. standing wave tubes; 12. loud speakers; 13. bottom reflection ends; 14. power amplifiers; 15. signal amplifiers.
Embodiment
Checkout gear and method below in conjunction with the drawings and specific embodiments to a kind of microphone high sound pressure-phase-shift characterisitc of the present invention are further described.
Embodiment 1
As shown in Figure 2, the checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc of the present invention, it comprises an equiphase coupling cavity 9 that falls " U " shape, equiphase coupling cavity 9 is fixedly connected on variable cross-section reflection end cap 10 tops of center with through hole; The through hole internal diameter of the internal diameter of equiphase coupling cavity 9 and variable cross-section reflection end cap 10 equates, and the external diameter of equiphase coupling cavity 9 is 1/2～1/3 times of the external diameter (for example: 1/2 times or 1/3 times) that variable cross-section reflects end cap 10.The top of standing wave tube 11 is fixedly connected on variable cross-section reflection end cap 10 belows, and the bottom of standing wave tube 11 is fixedly connected on bottom reflection end 13; The internal diameter of standing wave tube 11 is 2～3 times (for example: 2 times or 3 times) of the through hole internal diameter of variable cross-section reflection end cap 10, and the external diameter of standing wave tube 11 equals the external diameter of variable cross-section reflection end cap 10.By equiphase coupling cavity 9, variable cross-section reflection end 10, standing wave tube 11, a variable cross-section confined space of bottom reflection end 13 common compositions.
In standing wave tube 11, above bottom reflection end 13, be fixed with loud speaker 12.Loud speaker 12 connects power amplifier 14 by lead-out wire, and power amplifier 14 is gone back connecting signal source 3, and signal source 3 connects computer 5 again.Wherein, computer 5 control signal sources 3 connect power amplifier 14 and drive loud speaker 12 to send normal acoustic signals; The normal acoustic signals that loud speaker 12 sends multiple reflections in above-mentioned variable cross-section confined space forms high sound pressure stationary field, in stationary field, sound pressure level can reach 94～160dB (for example: 94dB, 140dB, 150dB or 160dB), sound wave distortion factor < 1%
In the two side of equiphase coupling cavity 9, symmetric position place opens mouth, is arranged on respectively passage port with reference to microphone 8 and proofing microphone 3.Also be connected signal amplifier 15 by lead-out wire respectively with reference to microphone 8 with proofing microphone 3, signal amplifier 15 connects computer 5 again.Wherein, monitor the sound pressure amplitude in equiphase coupling cavity 9 with reference to microphone 8, by signal amplifier 15, real-time sound pressure amplitude is passed to computer 5, then by the sound pressure amplitude in computer 5 control signal sources 3 and then control equiphase coupling cavity 9, form feedback control loop.
In equiphase coupling cavity 9, there is the equal characteristic of microphone symmetric position phase place, can obtain microphone high sound pressure-phase-shift characterisitc by witness mark microphone 8 from the phase difference of proofing microphone 3 under different sound pressure levels.
Embodiment 2
The detection method of the checkout gear of the microphone high sound pressure-phase-shift characterisitc described in employing embodiment 1, it comprises the steps:
(a) exported the sinusoidal signal of setpoint frequency f, sound pressure amplitude P0 by computer 5 control signal sources 3, then drive the loud speaker 12 in standing wave tube 11 to send acoustic signals by power amplifier 14; Setpoint frequency f is that 500～800Hz (for example: 500Hz, 600Hz, 700Hz or 800Hz), sound pressure amplitude P0 are 1～2000Pa (for example: 1Pa, 100Pa, 1000Pa or 2000Pa).
(b) loud speaker 12 in step (a) sends acoustic signals multiple reflections in variable cross-section confined space, form stable state stationary field, sound pressure amplitude and the phase place experienced with reference to microphone 8 and proofing microphone 1 are all equated, and sound pressure level reaches 94～160dB (for example: 94dB, 140dB, 150dB or 160dB), distortion factor < 1%;
(c) collect the sound pressure amplitude P0 in equiphase coupling cavity 9 with reference to microphone 8, by signal amplifier 15, real-time sound pressure signal is converted to electrical signal transfer to computer 5, these data of computer 5 real-time analysiss, and adjust the output amplitude of signal source 3, make the stable set point P0 that remains on of the interior sound pressure amplitude of equiphase coupling cavity 9, form close loop control circuit;
(d) signal collecting with reference to microphone 8 and proofing microphone 1 carries out Cross Spectra Analysis and obtains: the phase difference of proofing microphone 1 relative reference microphone 8 under frequency f, sound pressure amplitude P0 condition, obtains microphone high sound pressure-phase-shift characterisitc.
Claims (5)
1. a checkout gear for microphone high sound pressure-phase-shift characterisitc, is characterized in that: this device comprises equiphase coupling cavity (9), the variable cross-section reflection end cap (10), the standing wave tube (11) that fall " U " shape, bottom reflection end cap (13), loud speaker (12), power amplifier (14), signal source (3), computer (5), with reference to microphone (8), proofing microphone (1) and signal amplifier (15);
Wherein, equiphase coupling cavity (9) is fixedly connected on variable cross-section reflection end cap (10) top of center with through hole; The through hole internal diameter of the internal diameter of equiphase coupling cavity (9) and variable cross-section reflection end cap (10) equates, and the external diameter of equiphase coupling cavity (9) is less than variable cross-section and reflects the external diameter of end cap (10); The top of standing wave tube (11) is fixedly connected on variable cross-section reflection end cap (10) below, and the bottom of standing wave tube (11) is fixedly connected on bottom reflection end cap (13); The internal diameter of standing wave tube (11) is greater than the through hole internal diameter of variable cross-section reflection end cap (10), and the external diameter of standing wave tube (11) equals the external diameter of variable cross-section reflection end cap (10); Form a variable cross-section confined space by equiphase coupling cavity (9), variable cross-section reflection end cap (10), standing wave tube (11), bottom reflection end cap (13);
In standing wave tube (11), bottom reflection end cap (13) top is provided with loud speaker (12); Loud speaker (12) connects power amplifier (14) by lead-out wire, and power amplifier (14) is gone back connecting signal source (3), and signal source (3) connects computer (5) again; Wherein, computer (5) control signal source (3) connection power amplifier (14) drives loud speaker (12) to send normal acoustic signals; The normal acoustic signals that loud speaker (12) sends multiple reflections in above-mentioned variable cross-section confined space forms high sound pressure stationary field;
Symmetric position place, two side at equiphase coupling cavity (9) opens mouth, is arranged on respectively passage port with reference to microphone (8) and proofing microphone (1); Also be connected signal amplifier (15) by lead-out wire respectively with reference to microphone (8) with proofing microphone (1), signal amplifier (15) connects computer (5) again; Wherein, with reference to the sound pressure amplitude in microphone (8) monitoring equiphase coupling cavity (9), by signal amplifier (15), real-time sound pressure amplitude is passed to computer (5), then by the sound pressure amplitude in computer (5) control signal source (3) and then control equiphase coupling cavity (9); Can obtain microphone high sound pressure-phase-shift characterisitc by witness mark microphone (8) from the phase difference of proofing microphone (1) under different sound pressure levels.
2. the checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc according to claim 1, is characterized in that: the external diameter of described equiphase coupling cavity (9) is 1/2～1/3 times of external diameter of variable cross-section reflection end cap (10); The internal diameter of described standing wave tube (11) is 2～3 times of through hole internal diameter of variable cross-section reflection end cap (10).
3. the checkout gear of a kind of microphone high sound pressure-phase-shift characterisitc according to claim 1, it is characterized in that: the normal acoustic signals that described loud speaker (12) sends multiple reflections in variable cross-section confined space forms high sound pressure stationary field, in this stationary field, sound pressure level can reach 94～160dB, sound wave distortion factor <1%.
4. a detection method that adopts the checkout gear of any one microphone high sound pressure-phase-shift characterisitc described in claims 1 to 3, is characterized in that: the method comprises the steps:
(a) by the sinusoidal signal of computer (5) control signal source (3) output setpoint frequency f, sound pressure amplitude P0, then drive the loud speaker (12) in standing wave tube (11) to send acoustic signals by power amplifier (14);
(b) loud speaker (12) in step (a) sends acoustic signals multiple reflections in variable cross-section confined space, form stable state stationary field, sound pressure amplitude and the phase place experienced with reference to microphone (8) and proofing microphone (1) are all equated, and sound pressure level reaches 94～160dB, acoustic signals distortion factor <1%;
(c) collect the sound pressure amplitude P0 in equiphase coupling cavity (9) with reference to microphone (8), by signal amplifier (15), real-time sound pressure signal is converted to electrical signal transfer to computer (5), these data of computer (5) real-time analysis, and adjust the output amplitude of signal source (3), make the stable set point P0 that remains on of the interior sound pressure amplitude of equiphase coupling cavity (9), form close loop control circuit;
(d) signal collecting with reference to microphone (8) and proofing microphone (1) carries out Cross Spectra Analysis and obtains: the phase difference of proofing microphone (1) relative reference microphone (8) under frequency f, sound pressure amplitude P0 condition, obtains microphone high sound pressure-phase-shift characterisitc.
5. the detection method of a kind of microphone high sound pressure-phase-shift characterisitc according to claim 4, is characterized in that: described setpoint frequency f is that 500～800Hz, sound pressure amplitude P0 are 1～2000Pa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210044550.4A CN102655628B (en) | 2012-02-23 | 2012-02-23 | Device and method for detecting high sound pressure-phase shifting characteristic of microphone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210044550.4A CN102655628B (en) | 2012-02-23 | 2012-02-23 | Device and method for detecting high sound pressure-phase shifting characteristic of microphone |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102655628A CN102655628A (en) | 2012-09-05 |
| CN102655628B true CN102655628B (en) | 2014-07-23 |
Family
ID=46731145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210044550.4A Active CN102655628B (en) | 2012-02-23 | 2012-02-23 | Device and method for detecting high sound pressure-phase shifting characteristic of microphone |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102655628B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103781010B (en) * | 2012-10-25 | 2016-12-21 | 上海耐普微电子有限公司 | The test device of silicon microphone |
| CN103310782B (en) * | 2013-05-21 | 2015-06-17 | 东南大学 | Strong standing wave generation device for symmetric Helmholtz sound sources |
| US9813830B2 (en) | 2014-06-03 | 2017-11-07 | Intel Corporation | Automated equalization of microphones |
| CN104751835B (en) * | 2015-03-31 | 2018-11-13 | 中国飞机强度研究所 | A kind of rotation sound source generating means |
| CN105444874B (en) * | 2015-11-10 | 2018-10-26 | 株洲时代新材料科技股份有限公司 | A kind of sound intersity measurement calibrating installation and method |
| CN110099348A (en) * | 2018-01-29 | 2019-08-06 | 京元电子股份有限公司 | Has the microphone element test holder structure of more acoustical generators |
| CN109443515B (en) * | 2018-09-13 | 2021-05-14 | 中国船舶重工集团公司第七一五研究所 | System and method for testing sensitivity of small-size hydrophone in air |
| CN109121062B (en) * | 2018-10-17 | 2023-01-13 | 杭州兆华电子股份有限公司 | High sound pressure microphone testing arrangement |
| CN109916504B (en) * | 2019-04-10 | 2022-06-28 | 中国航空工业集团公司北京长城计量测试技术研究所 | Amplitude and frequency adjustable high-sound-pressure microphone calibrator with traceability |
| CN110113698B (en) * | 2019-05-10 | 2020-09-01 | 苏州静声泰科技有限公司 | Steady-state coupling cavity sound source with feedback control system |
| CN110248303B (en) * | 2019-05-30 | 2021-04-13 | 北京航天计量测试技术研究所 | Calibration method for microphone array precise calibration device |
| WO2021007872A1 (en) * | 2019-07-15 | 2021-01-21 | 中科新悦（苏州）科技有限公司 | High sound pressure microphone calibrating device, system and method |
| CN110473514A (en) * | 2019-08-02 | 2019-11-19 | 红河学院 | A kind of device and method obtaining Standing Waves of Finite Amplitude |
| CN111510840A (en) * | 2020-04-15 | 2020-08-07 | 中国电子科技集团公司第三研究所 | Frequency-adjustable high-sound-pressure-level microphone calibration device |
| CN112649087B (en) * | 2020-11-04 | 2022-11-18 | 北京航天计量测试技术研究所 | Noise sensor vibration sensitivity calibration method and device based on acoustic vibration decoupling |
| IT202000028430A1 (en) * | 2020-11-25 | 2022-05-25 | Leonardo Spa | MICROPHONE CALIBRATION METHOD, PARTICULARLY MICROPHONE FOR AERONAUTICAL USE |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02256398A (en) * | 1989-03-29 | 1990-10-17 | Ono Sokki Co Ltd | Calibration device for correcting characteristic difference |
| US5567863A (en) * | 1995-05-15 | 1996-10-22 | Larson-Davis, Inc. | Intensity acoustic calibrator |
| CN101895809A (en) * | 2010-07-01 | 2010-11-24 | 北京航空航天大学 | Microphone calibrator and calibration method thereof |
| CN202488715U (en) * | 2012-02-23 | 2012-10-10 | 北京航天计量测试技术研究所 | Detector of microphone high sound pressure-phase-shift characteristics |
-
2012
- 2012-02-23 CN CN201210044550.4A patent/CN102655628B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02256398A (en) * | 1989-03-29 | 1990-10-17 | Ono Sokki Co Ltd | Calibration device for correcting characteristic difference |
| US5567863A (en) * | 1995-05-15 | 1996-10-22 | Larson-Davis, Inc. | Intensity acoustic calibrator |
| CN101895809A (en) * | 2010-07-01 | 2010-11-24 | 北京航空航天大学 | Microphone calibrator and calibration method thereof |
| CN202488715U (en) * | 2012-02-23 | 2012-10-10 | 北京航天计量测试技术研究所 | Detector of microphone high sound pressure-phase-shift characteristics |
Non-Patent Citations (2)
| Title |
|---|
| 一种新的动态压力校准装置;张大有等;《宇航计测技术》;20111231;第31卷(第6期);第15-20页 * |
| 张大有等.一种新的动态压力校准装置.《宇航计测技术》.2011,第31卷(第6期), |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102655628A (en) | 2012-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102655628B (en) | Device and method for detecting high sound pressure-phase shifting characteristic of microphone | |
| CN102572671B (en) | Test method, test tool and test system for microphone tightness | |
| CN201976252U (en) | Microphone tightness testing tool and testing system | |
| CN102650545B (en) | High sound intensity level calibration device with combination of high sound pressure source and phase control and method | |
| CN104535647A (en) | Prediction apparatus for sound absorption and insulation performance of multilayer material and method | |
| CN109916504B (en) | Amplitude and frequency adjustable high-sound-pressure microphone calibrator with traceability | |
| KR101825363B1 (en) | Method and system for acquiring natural frequency of diaphragm | |
| EP2456229A1 (en) | Loudspeaker system and control method | |
| Hurst et al. | An experimental frequency response characterization of MEMS piezoresistive pressure transducers | |
| CN109900451B (en) | Method for correcting wind pressure signal distortion of wind tunnel experiment pressure measurement model | |
| CN103414978A (en) | Sound intensity instrument frequency response calibrating device of acoustic coupler method | |
| CN102384821B (en) | Loudspeaker module air tightness testing method, test fixture and test macro | |
| CN105403307A (en) | Noise detection comparison apparatus and method | |
| CN103813258A (en) | Method and system for acquiring diaphragm compliance | |
| CN202488715U (en) | Detector of microphone high sound pressure-phase-shift characteristics | |
| CN203466956U (en) | Amplitude and phase variable double-resonance sound wave generator | |
| CN106092306B (en) | A kind of acoustic pressure test method and acoustic pressure test macro | |
| JP2006329718A (en) | Device and method for measuring membrane stiffness | |
| Hoffmann et al. | Volumetric characterization of ultrasonic transducers for gas flow metering | |
| CN202485795U (en) | Loud intensity level calibration device of high sound pressure source combined with phase control | |
| CN107621495B (en) | Testing device and method for natural frequency of flexible film | |
| CN205228630U (en) | Noise detection compares device | |
| CN110958554B (en) | Debugging method and debugging system for hall audio-visual system | |
| KR101442797B1 (en) | Hearing aid calibrator | |
| CN107635184A (en) | A kind of test device of multifunction speaker |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |