29 results about "Sound level meter" patented technology

The application discloses a kind of for multi-scene adaptive power equipment intelligent inspection system, it is related to power equipment inspection field, wherein scene voiceprint modeling module is generated by laser radar scanning scene three-dimensional model and labels equipment identity data, and audio signal is collected to equipment, after extracting spectral feature, it is clustered, and it is constructed initial voiceprint model to remove anomaly;Adaptive learning module obtains real-time temperature with temperature sensor, calculates temperature influence coefficient and correction value, and obtains voiceprint baseline model by correcting initial model and is regularly updated;Inspection positioning module obtains the coordinates and attitude of inspection equipment, calculates its distance with equipment, azimuth angle, and generates predicted synthetic voiceprint data according to formula;Abnormality identification module compares real-time voiceprint data with prediction data, and identifies anomaly outside fluctuation range, and controls inspection equipment to move positioning abnormal equipment according to distance.The system solves the problem of multi-device sound source interference and temperature influence, and improves the reliability and abnormal positioning efficiency of inspection.

The invention provides a vibration noise detection device and method of a wall breaking machine, and mainly relates to the field of vibration noise detection. A vibration noise detection device of a wall breaking machine comprises a positioning mechanism arranged in a detection chamber and a plurality of noise detection mechanisms, coaxial placement and height adjustment of the wall breaking machine are achieved through clamping and positioning of the positioning mechanism, and the wall breaking machine can be located at the detection height on different workbenches. At least four noise detection mechanisms are arranged, each noise detection mechanism comprises a supporting arm, a supporting cavity is formed in the inner side of the front end of each supporting arm, a telescopic arm is arranged on each supporting cavity in a sliding mode, and a sound level meter and a distance sensor are arranged at the front end of each telescopic arm. The invention has the following beneficial effects: the invention creatively provides a structure and a method for respectively detecting noise by a plurality of workbenches, so that the noise intensity of the wall breaking machine in the daily use process can be more reasonably represented.

The invention relates to the technical field of sound insulation performance testing, and discloses a portable sound insulation performance testing device and a testing method thereof.The portable sound insulation performance testing device comprises a box body, a supporting assembly, a sound production unit, a sound level meter assembly and a dynamic signal tester; the supporting assembly is installed on the box body, a plate to be tested is installed on the supporting assembly, and the box body is divided into a sound source chamber and a receiving chamber; the sound production unit is mounted in the sound source chamber; the sound source chamber and the receiving chamber are internally provided with sound level meter assemblies used for collecting noise signals. And the dynamic signal tester is arranged outside the box body, is connected with the sound level meter assembly through a high-speed signal line assembly, and is used for receiving a signal of the sound level meter assembly. The device is simple in principle, convenient to install and easy to operate, the sound insulation testing efficiency can be greatly improved, and the testing energy consumption and cost are reduced.

This invention discloses an active coupling cavity device and calibration method for calibrating a standard microphone. A sound source adapter is located at the signal input end of the active coupling cavity. A multi-channel sound field distribution structure is located within the active coupling cavity, comprising eight acoustic channels evenly distributed circumferentially along the central axis of the active coupling cavity. A symmetrical clamping assembly constrains the reference microphone and the microphone under test to be symmetrical about the central axis of the active coupling cavity. A coaxiality test ring assembly rigidly constrains the axes of the reference microphone and the microphone under test to coincide with the central axis of the active coupling cavity. The calibration test system includes a signal generator, a sound level meter under test, a preamplifier, a measurement amplifier, a bandpass filter, and a digital voltmeter. The multi-channel uniformly distributed sound field structure solves the problem of uneven sound pressure distribution caused by unidirectional input, and the symmetrical clamping assembly and the coaxiality test ring assembly respectively solve the problem of poor consistency in low-frequency and high-frequency phase measurements.

System for detecting a leak in a water supply system, in particular a water supply system in a building, wherein several consumers can be supplied with water from the water supply system (8) and wherein each of the several consumers, when drawing water from the water supply system (8) - active consumer - emits sound into the water supply system (8), comprising: a flow measuring unit (3) designed to be attached to a supply line (5) of the water supply system (8) and to measure an actual flow rate through the supply line (5), a sound measuring unit (4) designed for attachment to the supply line (5) of the water supply system (8), for measuring sound in the water supply system (8) and for outputting sound measurement values ​​based on measured sound, wherein the sound measuring unit (4) is designed for detecting structure-borne sound, a sound evaluation unit (11) designed to detect active consumers based on sound measurement values, an estimation unit (12) designed to determine an estimated flow rate from the active consumers detected by the sound evaluation unit (11), and an evaluation unit (14) which is trained to compare the actual flow rate with the estimated flow rate and to detect a leak in the water supply system (8) based on a comparison result.

The invention provides an audio data processing method and system, electronic equipment and a storage medium, and the method comprises the steps: calling audio collection equipment to carry out the collection of biological sound audio, so as to obtain to-be-processed audio data; segmenting the audio data to be processed into a plurality of audio clips; calculating a cumulative percentage sound level of the audio clip; calculating the signal-to-noise ratio of the audio clip by using the cumulative percentage sound level; and according to the signal-to-noise ratio of the audio clip, identifying an effective audio clip from the plurality of audio clips. According to the scheme, the collected audio data to be processed are segmented into the plurality of audio clips; the signal-to-noise ratio of the audio clip is quickly calculated through the accumulated percentage sound level of the audio clip, and then the effective audio clip is identified from the plurality of audio clips according to the signal-to-noise ratio, so that the automatic audit of the audio is realized, and the audio audit efficiency and the audio audit accuracy are improved.

The utility model discloses a transformer sound level measurement auxiliary device, which comprises a plurality of sound level probes used for acquiring sound signals of a transformer, and further comprises a probe bearing frame covering the periphery of the transformer, and the plurality of sound level probes are arranged along the circumferential direction of the probe bearing frame. The sound level probes are located on the same horizontal plane, and the distances from the sound level probes to the outer surface of the transformer are equal. According to the utility model, the problem of inconsistent measurement distances caused by positioning deviation in traditional manual measurement is effectively solved, and the accuracy and reliability of measurement data are ensured; secondly, the sound level meter does not need to be held manually or the position of the measuring head does not need to be adjusted frequently, the electric shock safety risk possibly faced by manual operation under the electrified working condition is greatly reduced, and the personal safety of operators is guaranteed; and multiple measuring points can be measured at the same time, so that the condition of long time consumption of a single test caused by manual switching measurement of multiple measuring points in the prior art is changed, and the detection efficiency is greatly improved.

The application discloses a road traffic noise crowd influence measurement method based on mobile phone signaling data, and the method comprises the following steps: acquiring mobile phone signaling data, determining the space-time distribution information of mobile phone signaling users, estimating the actual population space-time distribution according to the space-time distribution information of mobile phone signaling users and local population census data, calculating the residence time of users staying at each base station position according to the population age attribute in the mobile phone signaling data and the population activity characteristics in the actual population space-time distribution, and then determining a target data set; combining the hourly traffic noise map of the city to obtain the hourly traffic noise equivalent sound level of the coverage range of each base station, and calculating the road traffic noise continuous exposure intensity of the target crowd according to the target data set and the traffic noise equivalent sound level. The application has high accuracy and can be widely applied to the field of computer technology.

The utility model provides building environment noise detection equipment, belongs to the technical field of building engineering management, and aims to solve the problems that an existing sound level meter needs to be temporarily heightened by means of bricks and other objects in a building construction site to ensure the accuracy of a measurement result, operation is tedious, and extra errors are possibly introduced due to unstable supporting. Comprising a sound level meter body, a palm elastic band, an arm elastic band, a linkage placing assembly and a portable assembly. The two palm elastic bands are fixedly connected to the left side and the right side of the sound level meter body respectively. The arm elastic band is arranged behind the top of the sound level meter main body; the linkage placing assemblies are arranged on the left side, the right side and the bottom of the sound level meter body. And the portable assembly is arranged behind the top of the sound level meter main body. According to the utility model, the sound level meter main body can be magnetically attracted on an iron building structure and is matched with the three-legged telescopic support frame, so that the sound level meter main body adapts to detection operation in various complex environments, and the sound level meter main body can be fixed on an arm, so that the operation safety is guaranteed.

The utility model discloses a detection device for environmental engineering, which belongs to the technical field of environmental engineering, and comprises a sound level meter, the rear side of the sound level meter is movably connected with a split type disassembly and assembly mechanism, the rear side of the split type disassembly and assembly mechanism is movably connected with a flexible fixing mechanism, and the flexible fixing mechanism is movably connected with the sound level meter. The contradiction between portability and practicability of traditional long-time detection equipment can be solved, the problem that a traditional support is large in size and inconvenient to carry is solved by overturning and storing the clamping rods to the inner side of the fixed bottom plate and fixing the clamping rods through magnetic attraction, the portability is greatly improved, and an electronic telescopic rod is matched with a rotary knob to drive the clamping rods to conduct bidirectional clamping. The device can be rapidly installed on various carriers such as lampposts and trees without additional tools, traditional installation point position limitation is broken through, clamping rod lines enhance friction force, a ratchet and pawl structure locks a knob to prevent looseness, the installation stability in severe weather is effectively improved, the device is integrally compatible with various carriers such as wooden and metal rod bodies, and the installation cost is reduced. And the application scene of long-time detection is expanded.

An IoT Smart Sound Level Meter that is connected through the internet via ethernet cable, wifi or cellular network. The IoT Smart Sound Level Meter measures and monitors sound pressure levels. Sound pressure levels are measured in decibels. The sound pressure level data that is sent via the internet through ethernet, wifi or cellular network to cloud servers where the data is stored and saved. The cloud servers are connected to Application Programming Interfaces (API) connected to web-based software that converts the sound pressure level data into decibel measurements. These measurements are displayed to the end-user through the web-based software and / or application providing real-time decibel level measurements and historic sound pressure level recordings. The web-based software and / or application provides access to view decibel measurement data remotely from a computer, laptop, tablet, smart watch, or mobile device.

The utility model belongs to noise detection technical field, specifically disclose an improved wind power noise test is with noise signal collection equipment, including sound level meter and wireless device, wireless device includes the equipment cabinet that lies on the ground, is equipped with antenna mast structure on the equipment cabinet, is equipped with antenna support on antenna mast structure, has fixed structure on antenna mast structure, fixed structure includes the eye -splicing, the eye -splicing is fixed on the ground through the wind rope of inclination setting and the ground peg of wind rope bottom end, and the ground peg is symmetrically set up in the periphery of equipment cabinet, antenna support includes the connecting seat that sets up in the top of antenna mast structure, the lateral rod that is symmetrically set up with both sides of connecting seat, the lateral rod end is connected with the antenna through detachable structure, the top clearance of connecting seat is equipped with LED lamp and photosensitive switch.

The utility model discloses a sound level meter support for detecting automobile noise, which comprises a supporting assembly and a fixed placing assembly, the fixed placing assembly is arranged at the top of the supporting assembly, the supporting assembly is used for supporting the fixed placing assembly, and the fixed placing assembly is used for installing a sound level meter; the device is simple in structure and reasonable in design, through the arrangement of the supporting assembly and the fixed placing assembly, the measurement accuracy is improved, the device can be rapidly installed and adjusted on site, and the stability is enhanced.

The utility model belongs to the technical field of noise detection, and particularly relates to a noise acquisition device for intelligent mechanical equipment. Comprising a sound level meter body, a windproof cover is detachably installed on a microphone at one end of the sound level meter body, a containing groove is formed in the bottom of the sound level meter body, a telescopic support is arranged in the containing groove, and a motor used for driving the telescopic support to rotate relative to the sound level meter body is arranged in the sound level meter body. Space limitation is broken through through the telescopic support, the problem that an existing sound level meter is difficult to operate manually in narrow spaces such as the interior of a mechanical arm and an equipment interlayer is solved, the telescopic support can be remotely controlled to be unfolded, the angle can be adjusted, the microphone can be accurately aligned with a sound source, measured numerical values are more accurate, and operation is more convenient. And in cooperation with rapid disassembly and assembly of the magnetic type windshield and anti-interference design, full-automatic noise collection under complex working conditions is achieved, the feasibility and accuracy of noise detection of a closed space in the fields of automobile manufacturing and mechanical equipment machining are greatly improved, and the use requirements of users are met.

The invention discloses a high-accuracy measurement method and equipment for a sound level test of a distribution transformer. The high-accuracy measurement method for the sound level test of the distribution transformer comprises the following steps: obtaining the external dimension and height information of the distribution transformer, obtaining a reference emission surface of the distribution transformer through a deep learning image segmentation algorithm, and carrying out smooth processing through a data fitting algorithm to obtain a specified contour line required by the test; measuring points are uniformly distributed on the contour line, a sound level meter and wireless transmission equipment are fixed, a distribution transformer wiring preparation test is completed, background noise is measured before the test and a result is uploaded, distribution transformer noise is measured in the test and a result is uploaded, background noise is measured after the test and a result is uploaded, and the effectiveness of the distribution transformer test noise is verified. If the conditions are not met, the background noise measurement before the test is carried out again after correction. The method provided by the invention can solve the problems of complex process, low accuracy and too low efficiency of the existing transformer sound level measurement method.

This invention discloses a portable sound source for sound level meter testing, comprising: a semi-in-ear earphone as a sound-generating unit; a sound guide tube, with the semi-in-ear earphone disposed at the front end of the sound guide tube for conducting sound waves; a limiting component disposed at the rear end of the sound guide tube for limiting the insertion depth of the sound level meter microphone; a microphone index tube disposed at the rear end of the limiting component for fixing the sound level meter microphone; and an external shock-absorbing and sound-insulating tube covering the exterior of the above components. This portable sound source for sound level meter testing uses a semi-in-ear earphone and common tubing for assembly, making it easy to manufacture and promote. It is also small in size and lightweight, requiring no external power supply, and suitable for on-site sound level meter testing. This solution provides a single sound source covering the 20Hz-16kHz frequency band, eliminating the need for equipment switching, simplifying the operation process, and achieving integrated testing across the entire frequency band. Furthermore, it exhibits high sound field stability and good sound field uniformity.

The invention discloses a power equipment intelligent inspection system for multi-scene self-adaption, and relates to the field of power equipment inspection, a scene voiceprint modeling module generates a scene three-dimensional model through laser radar scanning and marks equipment identity data, and a sound level meter is arranged to collect equipment audio signals; clustering after extracting frequency spectrum features, and eliminating anomalies to construct an initial voiceprint model; the adaptive learning module obtains real-time temperature by using a temperature sensor, calculates a temperature influence coefficient and a correction value, corrects the initial model to obtain a voiceprint baseline model, and updates the voiceprint baseline model regularly; the inspection positioning module acquires coordinates and postures of inspection equipment, calculates a distance and an azimuth angle between the inspection equipment and the equipment, and generates predicted synthetic voiceprint data according to a formula; and the abnormity identification module collects real-time voiceprint data, compares the real-time voiceprint data with prediction data, identifies abnormity when the fluctuation range is exceeded, and controls the inspection equipment to move and position abnormal equipment according to the distance. According to the system, the problems of multi-device sound source interference and temperature influence are solved, and the routing inspection reliability and the abnormity positioning efficiency are improved.

Managing sound levels at an IHS, including determining, for each time duration over a first time period, multiple instantaneous sound levels of the time duration of an environment of the IHS; calculating, for each time duration over first time period, an average sound level of the time duration based on the multiple instantaneous sound levels of the time duration; determining, based on the average sound level of each time duration over the first time period, a lowest average first sound level for first time period; setting the lowest average first sound level as an ambient sound level of the environment of the IHS for the first time period; adjusting, for the first time period, a fan speed of a fan based on the ambient sound level of environment such that a noise level of the fan is less than the ambient sound level of environment for the first time period.

This application relates to the field of sampling and calibration device technology, and more particularly to an automatic sampling and calibration device for multi-point environmental parameters in space. The technical solution includes a main control device and at least one movable measuring platform. The main control device integrates a hygrometer, a dust particle counter, a differential pressure sensor, a sound level meter, an illuminance meter, a fiber optic temperature sensor, and an anemometer. The movable measuring platform integrates a fiber optic temperature sensor and a hygrometer. Both the main control device and the movable measuring platform are equipped with lifting devices and laser rangefinders, respectively used for sensor height adjustment and automatic positioning. The main control device has a control unit that controls each device to move to a designated point and rise to a set height according to a preset program, simultaneously collecting multiple environmental parameters and generating a calibration report. This application achieves efficient, accurate, and automated calibration of environmental parameters through integrated design, automatic positioning and lifting, and multi-machine collaborative control.

The invention discloses a microphone testing device which comprises an anechoic chamber, a standard sound source and a fixing assembly are horizontally and oppositely arranged in the anechoic chamber, the fixing assembly comprises a telescopic cross rod, a fixing rod and a telescopic rod, and the fixing rod is fixed to the anechoic chamber; the sliding vertical rod is vertically connected to the telescopic rod in a sliding manner; the telescopic scale is transversely and slidably connected to the telescopic rod; the upper end of the sliding vertical rod is connected with a rotating seat, a sound level meter to be tested and a standard microphone are installed at the two ends of the rotating seat in a back-to-back mode, and the telescopic rod, the sliding vertical rod and the telescopic ruler are all provided with scales. The objective of the invention is to solve the problems in the prior art that when the temperature drift of a standard sound source needs to be switched for measurement, the positioning operation of a standard microphone and a sound level meter to be measured is tedious, the precision is low, the repeatability is poor, and a support structure may introduce sound reflection interference.

The invention relates to the technical field of electric vehicle detection, in particular to an electric vehicle warning tone test method and system based on a CAN bus and sound pressure detection, and the method comprises the steps: importing an ECU parameter reference list, and inputting a standard sample sound pressure level reference value and a set allowable offset; putting a product to be tested into a special tool clamp, connecting a product power interface and a CAN bus interface, aligning a sound level meter microphone to a product sound production hole position, and keeping the distance at a standard specified position; reading the parameters of the product to be tested through the CAN bus, comparing the parameters with reference values in the ECU parameter reference list one by one, if all the parameters are consistent, entering the next step, otherwise, giving an alarm and terminating; and triggering the product to make a sound, collecting a sound pressure level through a sound level meter, calculating an error between the sound pressure level and a standard sound pressure level reference value, judging whether the error is within a preset offset range, if so, passing the judgment, and otherwise, giving an alarm and terminating. The skill requirements on operators are greatly reduced, and the detection efficiency is improved.

1. The name of the design product: sound level meter (KE523A). 2. The use of the design product: for environmental noise detection. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The utility model relates to the technical field of vehicle testing, and provides a sound level meter mounting bracket and a vehicle noise testing device. The sound level meter mounting bracket comprises a back hanging type mounting piece, a first connecting piece, a second connecting piece, a sound level meter fixing piece and a locking piece, a first connecting piece is connected to the back-hanging type installation piece in a sliding mode, the end of the first connecting piece is connected to a second connecting piece in a sliding mode, a sound level meter fixing piece is connected to the second connecting piece, and the two ends of the locking piece are connected to the first connecting piece. The support is connected with a seat through the back hanging type installation piece, the back hanging type installation piece is hooked on the seat, and the support is suitable for a seat with a separated headrest and a backrest and is also suitable for a seat with an integrated headrest and the backrest. According to the support, the sound level meter can be fixed at a preset test point, the installation stability of the sound level meter is guaranteed, and the support is high in flexibility and can be suitable for various test scenes.

The invention discloses a sound level meter A weighting filter design method based on IWOA and a measuring device. The method comprises the steps that a target sub-filter needing to be optimized in a sound level meter A weighting filter is determined; performing digital modeling on the target sub-filter to obtain a digitized filter model, establishing constraint conditions for the digitized filter model, and constructing a target optimization function to obtain an optimization problem model of the target sub-filter; and performing parameter optimization on the optimization problem model by adopting an improved whale optimization algorithm IWOA to obtain optimal parameters in the digitized filter model, thereby obtaining an optimized target sub-filter. The invention aims to reduce the error of the A weighting filter in the sound level meter, ensure the overall measurement accuracy of the sound level meter, reduce the influence of measurement uncertainty, and enable the sound level meter to make accurate response to noise of various frequencies in various complex occasions.

The utility model provides an automatic moving and positioning device for testing, and particularly relates to the technical field of sound pressure level testing. An automatic moving and positioning device for testing comprises a moving vehicle body, moving wheels are symmetrically arranged on the two sides of the bottom of the moving vehicle body respectively, the moving wheels are connected with stepping motors respectively, and a base motor is arranged on the upper portion of the moving vehicle body and rotationally connected with a mechanical arm base. First rotating arm motors are arranged on the two sides of the mechanical arm base correspondingly and rotationally connected with the first rotating arm. The beneficial effects of the utility model are that according to a set route, the stepping motor drives the moving wheel to rotate around the tested equipment, and the first rotating arm and the second rotating arm rotate up and down to adjust the up and down height; a microphone of a specific sound level meter can be rapidly placed at a standard specified position for sound pressure level testing, and meanwhile, the rotating arm motor can adjust the measuring angles of the laser distance measuring sensor and the sound level meter.

The utility model relates to the technical field of sound insulation testing, in particular to a sound insulation testing device for plates. The sound insulation testing device comprises a semi-closed box body with a containing space, a sounder and a sound level meter. The box body comprises a box body shell with the top open, the multi-layer composite sound insulation structure is arranged on the inner wall of the box body shell and forms a containing space in an enclosing mode, the sounder is arranged in the containing space, and a board to be tested can be placed on the top of the multi-layer composite sound insulation structure. The multi-layer composite sound insulation structure comprises a mass layer, an outer sound insulation layer, a damping layer, a sound absorption layer, an inner sound insulation layer and an anti-reverberation layer which are sequentially arranged from outside to inside, and the sound level meter is arranged over the box body. The sound insulation testing device is simple in structure, easy to reproduce and low in cost. The device is simple in testing step and high in consistency, can perform sound insulation effect comparison and judgment in a laboratory stage, is simple and convenient, and is helpful for sound insulation plate research in a laboratory.

The utility model relates to the technical field of sound level meters, in particular to a sound level meter external supporting mechanism which comprises a pipe sleeve, a supporting rod is arranged at the top end of the pipe sleeve in a sleeved mode, the bottom end, located in the pipe sleeve, of the supporting rod is connected with a first piston through a threaded groove, and an angle adjusting assembly is arranged at the top end of the supporting rod. The angle adjusting assembly comprises a structural frame fixed to the top end of the supporting rod through a bolt, a gear is rotationally connected into the structural frame through a bearing, a connecting column is welded to one side of the gear, and a clamping cover is fixed to one end of the connecting column through a bolt. An air inlet assembly is arranged on one side of the pipe sleeve; the second piston is pulled up and down through the connecting rod, external air is pumped into the barrel and conveyed into the pipe sleeve, the supporting rod and the sound level meter fixed to the clamping cover are pushed to move upwards through the first piston, a power source does not need to be connected, the clamping cover and the sound level meter in the clamping cover can be adjusted to rotate through the connecting column by rotating the gear, and the inclination angle of the sound level meter can be adjusted.

The application discloses a sound level testing device for new energy vehicles, which comprises a testing frame and a sound level meter. The sound level meter is arranged on the testing frame and is used for measuring the sound level of the surroundings. The sound level meter is provided with a detection head used for testing and a wind noise cover sleeved on the detection head and used for protecting the detection head. The sound level meter is further provided with a measuring unit. The measuring unit comprises a sound emitting piece used for measuring the permeability of the wind noise cover and an isolation cover. The sound emitting piece is used for emitting a specific sound pressure to the detection head. The sound level testing device for new energy vehicles can automatically measure the permeability of the wind noise cover before each test and automatically blow and clean when the measurement is unqualified, so as to ensure the accuracy of each sound level test. Therefore, the sound level testing device can accurately test the sound level in a humid or windy environment, and can truly record the accurate sound level of the new energy vehicles in various environments.

The utility model relates to the technical field of sound equipment, in particular to a sound capable of being automatically calibrated, which comprises a sound main body, a microphone and a loudspeaker are respectively arranged on the outer side of the sound main body, rear fastening blocks are respectively arranged on the left side and the right side of the sound main body, and positioning holes are formed in the rear side surfaces of the rear fastening blocks. The sound equipment comprises a sound equipment main body, a maintenance cover plate is arranged on the front side of the sound equipment main body, front fastening blocks are fixedly installed on the left side and the right side of the maintenance cover plate, positioning columns are fixedly installed on the rear sides of the front fastening blocks, limiting blocks are arranged at the rear ends of the positioning columns, and a sound level device, an adjusting controller and a main control module are arranged in the sound equipment main body. According to the sound equipment capable of being automatically calibrated, the structural design of the microphone, the sound level device, the main control module and the adjusting controller is utilized, so that the aim of calibration is achieved, the applicability of the sound equipment is improved, and the sound quality effect of the sound equipment is ensured.