Patent Publication Number: US-2013251160-A1

Title: Pure tone test apparatus and method for controlling the same

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Patent Application No. 10-2012-0028273, filed on Mar. 20, 2012, entitled “Pure Tone Test Apparatus and Control Method Thereof”, which is hereby incorporated by reference in its entirety into this application. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a pure tone test apparatus and a method for controlling the same. 
     2. Description of the Related Art 
     Most electronic devices, or the like, may generate large and small driving noise in terms of characteristics of a structure thereof. In worse case scenarios, the driving noise from electronic devices, or the like, may cause pain and stress to users. Therefore, minimizing the driving noise of electronic devices, or the like, is one of the fundamental problems to be solved in order to improve the quality of human life. Recently, various devices have been developed or various methods have been attempted to minimize the noise. 
     Meanwhile, in order to efficiently reduce the noise, there is a need to generate reliable noise information by accurately measuring noise from noise sources. However, as described in Korean Laid-Open Patent No. 2005-0119290 (Publication in Dec. 21, 2005) as the prior art, an anechoic room for professionally measuring and evaluating noise should be included in order to evaluate pure tone noise of electronic devices such as a hard disk drive (HDD). 
     A noise degree of products has been evaluated in a state in which the anechoic room is included along with various noise measuring devices that also need to be included so as to meet the international standards. Even though the noise evaluation method for products has high accuracy, the noise evaluation method has problems in that considerable costs are consumed and it requires a lot of time and effort. In particular, for mass production, it is impossible to test all the products one by one and it is difficult to evaluate the noise from products using only the sampling test. 
     In addition, when objects causing noise such as a computer, or the like, are present around the anechoic room, the noise evaluation method in accordance with the prior art may distort the pure tone of products. 
     In particular, since the measurement distance between a product and a microphone is spaced apart from each other in the anechoic room, the sound quality evaluation may greatly change according to conditions and situations, and thus, noise cannot be objectively measured. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in an effort to provide a pure tone test apparatus capable of easily testing a pure tone test of electronic devices during a production process. 
     In addition, the present invention has been made in an effort to provide a method for controlling a pure tone test apparatus capable of measuring only pure tone noise of electronic devices by blocking background noises as maximally as possible. 
     According to a preferred embodiment of the present invention, there is provided a pure tone test apparatus, including: a stage including a support supporting to a pure tone test target; a support plate mounted on one side of the stage and having a guide mounted on a front surface thereof; an acoustic detection unit movably mounted on the guide and being engaged with the support to detect noise generated from the target; a control unit connected with the guide, the acoustic detection unit, and the support to control a pure tone test; and a display unit displaying a pure tone test result detected by the control of the control unit. 
     The pure tone test apparatus may further include: soundproof plates mounted at both sides of the stage based on the support. 
     The support may be formed to be sealed by being engaged with the acoustic detection unit and to connect a power supply to the pure tone test target. 
     The acoustic detection unit may include: a microphone detecting the noised generated from the pure tone test target; a housing having sides surrounding the microphone and including a drawing hole through which a cable line connected to the microphone is drawn; and an opened type shielding cover extendedly formed integrally from a lower opening part of the housing. 
     The pure tone test apparatus may further include: sound absorbing and insulating parts mounted on both sides of the housing and including a soundproof material and sound absorbing material provided therein, the soundproof material blocking background noise therein and the sound absorbing material absorbing noise caused by the reflection and overlapping transfer of the noise from the target from an inner surface of the housing. 
     According to another preferred embodiment of the present invention, there is provided a method for controlling a pure tone test apparatus, including: generating noise by supporting a pure tone test target on a support and supplying power thereto and forming a shielding space by engaging a shielding cover of an acoustic detection unit with the support; detecting noise generated from the target through a microphone of the acoustic detection unit; transforming, by a control unit, detected noise information into replacing acoustic information by using an acoustic compensation algorithm; determining, by the control unit, whether a spectrum according to the replacing acoustic information has a value larger than that of a spectrum of a transfer function from the target to a noise detector in an anechoic room; setting, by the control unit, an evaluation reference spectrum for evaluating the pure tone of the target according to a result of the determining; and performing, by the control unit, the pure tone evaluation of the target by using a prominence ratio (PR) value calculated for the pure tone evaluation of the target. 
     At the transforming of the replacing acoustic information, the acoustic compensation algorithm may satisfy a relationship equation of 
     
       
         
           
             
               
                 
                   
                     
                       G 
                       
                         jj 
                         A 
                       
                     
                      
                     
                       ( 
                       f 
                       ) 
                     
                   
                   = 
                     
                    
                   
                     
                       
                         r 
                         jb 
                         2 
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                     × 
                     
                       
                         G 
                         
                           bb 
                           A 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                   
                 
               
             
             
               
                 
                   = 
                     
                    
                   
                     
                       
                         H 
                         ij 
                       
                       
                         H 
                         ab 
                       
                     
                     × 
                     
                       
                         
                           G 
                           
                             bb 
                             A 
                           
                         
                          
                         
                           ( 
                           f 
                           ) 
                         
                       
                       . 
                     
                   
                 
               
             
           
         
       
     
     (where G jj     A   (f) represents a spectrum according to the replacing acoustic information, r jb   2  represents an output spectrum correlation coefficient between the anechoic room in accordance with the related art and the shielding space, G bb     A   (f) represents a noise output spectrum of the target included in the shielding space between the support and the shielding cover, H ij  represents a transfer function from the target to a noise detector in the anechoic room in accordance with the related art, and H ab  represents a transfer function from the target to a microphone in the shielding space). 
     The setting of the evaluation reference spectrum may include defining, by the control unit, the spectrum according to the replacing acoustic information as an evaluation reference spectrum for evaluating the pure tone of the target if it is determined that the spectrum according to the replacing acoustic information has a value larger than that of the spectrum of the transfer function from the target to the noise detector in the anechoic room. 
     The setting of the evaluation reference spectrum may include making, by the control unit, the value of the spectrum according to the replacing acoustic information and the value of the spectrum of the transfer function from the target to the noise detector in the anechoic room equal to each other, if it is determined that the spectrum according to the replacing acoustic information has a value equal to or smaller than that of the spectrum of the transfer function from the target to the noise detector in the anechoic room; and defining, by the control unit, the equalized spectrum as the evaluation reference spectrum for evaluating the pure tone of the target. 
     At the performing of the pure tone evaluation, the pure tone evaluation of the target may be performed by using the PR value for a critical band of the evaluation reference spectrum. 
     At the performing of the pure tone evaluation, the pure tone evaluation of the target may be performed by using the PR value through octave analysis on the evaluation reference spectrum. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a diagram for describing a configuration of a pure tone test apparatus in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is an enlarged perspective view of an acoustic detection unit of the pure tone test apparatus shown in  FIG. 1 ; 
         FIG. 3  is a flow chart for describing a method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention; 
         FIG. 4A  is a diagram showing an acoustic spectrum detected by the method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention; 
         FIG. 4B  is a diagram showing a spectrum obtained by processing the acoustic spectrum detected by the method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention using an acoustic algorithm; and 
         FIG. 5  is an acoustic spectrum measured in the real anechoic room. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The objects, features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant descriptions thereof are omitted. Further, in the following description, the terms “first”, “second”, “one side”, “the other side” and the like are used to differentiate a certain component from other components, but the configuration of such components should not be construed to be limited by the terms. Further, in the description of the present invention, when it is determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof will be omitted. 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a diagram for describing a configuration of a pure tone test apparatus in accordance with a preferred embodiment of the present invention and  FIG. 2  is an enlarged perspective view of an acoustic detection unit of the pure tone test apparatus shown in  FIG. 1 . 
     A pure tone test apparatus  100  in accordance with a preferred embodiment of the present invention includes a stage  110  having a support  111  supporting a pure tone test target  200  disposed on a top surface thereof, soundproof plates  115  disposed at both sides of the stage  110  based on the support  111 , a support plate  120  disposed on a back of the stage  110  and having a guide  125  disposed on a front surface thereof, an acoustic detection unit  130  vertically movable fastened with the guide  125  and engaged with the support  111  to detect noises generated from the pure tone test target  200 , a control unit  140  connected to a guide  125 , an acoustic detection unit  130 , the support  111 , or the like, to control the pure tone test, and a display unit  150  displaying results detected by the control of the control unit  140 . 
     The support  111  is a portion that is mounted on a top surface of the stage  110  for supporting a pure tone test target  200 , for example, a product mounted with a motor, such as, a hard disk drive (HDD), an optical disc drive (ODD), or the like, or a motor. The support  111  may have a form supported to surround the pure tone test target  200  and may have a sealed structure in which the top thereof is engaged with the acoustic detection unit  130 . In this configuration, the support  111  selectively interworks with a conveyor belt or a transfer robot and is thus continuously supported with a product that is the pure tone test target  200  during mass production. Therefore, the product may be tested and separated on and from the support  111 . 
     The guide  125  is mounted on the front of the support plate  120  that is mounted on the back of the stage  110  and a rail or a concave groove line formed at one side thereof is fastened with the acoustic detection unit  130  and the guide  125  may vertically move the acoustic detection unit  130  using a roller or a bearing by a hydraulic or pneumatic sliding manner. 
     As shown in  FIG. 2 , the acoustic detection unit  130  includes a microphone  130 - 5  detecting the noise generated from the pure tone test target  200 , a housing  132  having sides surrounding the microphone  130 - 5  and having one side thereof including a drawing hole  134  through which a cable line connected with the microphone  130 - 5  is drawn, an opened type shielding cover  131  extendedly formed integrally from a lower opening part of the housing  132 , and sound absorbing and insulating parts  133 - 1  and  133 - 2  selectively mounted at both sides of the housing  132 . 
     The microphone  130 - 5  is disposed on a housing  132  at a distance from the lower opening part of the housing  132  so as to detect the noise generated from the target  200  and is connected with the cable line drawn in through the drawing hole  134  to be operated according to a control of the control unit  140 . 
     The shielding cover  131  is engaged with the outside of the support  111  by extending the lower opening part of the housing  132  and forms a shielding space surrounding the target  200  together with the support  111 . In addition, a lower edge  131 - 2  of the shielding cover  132  is made of an elastic material such as rubber, silicon, or the like, to reduce impact and improve shielding efficiency of a shielding space during the engagement with the support  111 . Further, the shielding cover  131  in addition to the lower edge  131 - 2  of the shielding cover  131  may be made of the elastic material such as rubber, silicon, or the like. 
     The sound absorbing and insulating parts  133 - 1  and  133 - 2  are selectively mounted at both sides of the housing  132  as the left sound absorbing and insulating part  133 - 1  and the right sound absorbing and insulating part  133 - 2  and the inside thereof is provided with a soundproof material that blocks background noise rather than the noise from the target  200  and a sound absorbing material that absorbs noise generated due to the reflection and overlapping transfer of the noise generated from the target  200  from the inside of the housing  132 . 
     The control unit  140  is connected with the guide  125 , the acoustic detection unit  130 , the support  111 , or the like, and may be mounted the outside or at one side of the support plate  120 . The control unit  140  controls the pure tone test to transform the noise from the target  200  detected by the acoustic detection unit  130  using an acoustic algorithm, calculates a prominence ratio (PR) value using the transformed results, and displays the pure tone evaluation of the target  200  on the display unit  150  according to the calculated PR value. 
     The pure tone test apparatus  100  described as above in accordance with the preferred embodiment of the present invention performs the noise measurement for the target  200  in the shielding space formed by the support  111  and the shielding cover  131  so as to prevent noise from being introduced from the outside. To this end, the pure tone test apparatus  100  supports the target  200  on the support  111  and supplies power to the target  200 . 
     Therefore, the pure tone test apparatus  100  in accordance with the preferred embodiment of the present invention uses the PR value obtained by transforming the detected noise of the target  200  according to the acoustic algorithm without performing the pure tone evaluation in the expensive anechoic room in accordance with the related art, thereby easily performing the pure tone evaluation of the target  200 . 
     Hereinafter, a method for controlling the pure tone test apparatus for performing the pure tone evaluation of the target  200  in accordance with another preferred embodiment of the present invention will be described with reference to  FIGS. 3 to 5 .  FIG. 3  is a flow chart for describing a method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention,  FIG. 4A  is a diagram showing an acoustic spectrum detected by the method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention,  FIG. 4B  is a diagram showing a spectrum obtained by processing the acoustic spectrum detected by the method for controlling a pure tone test apparatus in accordance with another preferred embodiment of the present invention using an acoustic algorithm, and  FIG. 5  is an acoustic spectrum measured in the real anechoic room. 
     As shown in  FIG. 3 , the method for controlling a pure tone test apparatus for performing the pure tone evaluation of the target  200  in accordance with another preferred embodiment of the present invention first supports the target  200  on the support  111  and supplies power to the target  200  to generate noise therefrom (S 310 ). 
     That is, the products mounted with a motor such as HDD, ODD, or the like, or the target  200  including a motor is supported on the support  111  and power is supplied to the target  200  so as to be mounted. 
     As described above, since the target  200  is mounted on the support  111 , the target  200  generates noise. In this case, the shielding cover  131  of the acoustic detection unit  130  disposed over the support  111  is engaged with the support  111  according to the control of the control unit  140  to form the shielding space. 
     After shielding cover  131  is engaged with the support  111  to form the shielding space, the control unit  140  controls the acoustic detection unit  130  to detects the noise generated from the target  200  trough the microphone  130 - 5  (S 320 ). 
     In this case, in order for the microphone  130 - 5  spaced apart from the shielding space to accurately detect the noise generated from the target  200 , the sound absorbing and insulating parts  133 - 1  and  133 - 2  may be selectively provided so as to prevent the noise generated due to the reflection and overlapping transfer of the external noise or the noise from the target  200  from the inner surface of the housing  132  from incoming into the microphone  130 - 5 . 
     According to the detection of the noise generated from the target  200  through the microphone  130 - 5 , the control unit  140  transforms the noise information detected using the acoustic compensation algorithm into the replaceable acoustic information (S 330 ). 
     In detail, the acoustic compensation algorithm is represented by the relationship Equation described in the following [Equation 1]. 
     
       
         
           
             
               
                 
                   
                     
                       G 
                       
                         jj 
                         A 
                       
                     
                      
                     
                       ( 
                       f 
                       ) 
                     
                   
                   = 
                     
                    
                   
                     
                       
                         r 
                         jb 
                         2 
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                     × 
                     
                       
                         G 
                         
                           bb 
                           A 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                   
                 
               
             
             
               
                 
                   = 
                     
                    
                   
                     
                       
                         H 
                         ij 
                       
                       
                         H 
                         ab 
                       
                     
                     × 
                     
                       
                         G 
                         
                           bb 
                           A 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                   
                 
               
             
           
         
       
     
     (G jj     A   (f) represents a spectrum according to the replacing acoustic information, r jb   2  represents an output spectrum correlation coefficient between the anechoic room, G bb     A   (f) represents a noise output spectrum of the target  200  included in the shielding space between the support  111  and the shielding cover  131 , H ij  represents a transfer function from the target  200  to a noise detector (microphone) in the anechoic room in accordance with the related art, and H ab  represents a transfer function from the target  200  to the microphone  130 - 5  in the shielding space). 
     In the above Equation, the transfer function H is a function representing the relationship between an input wave and an output wave generally having linear characteristics. That is, as represented by the following [Equation 2], the transfer function (H) is defined by a ratio of a Laplace transform Y(s) of an output wave y(t) to a Laplace transform X(s) of the input wave x(t). 
     
       
         
           
             
               
                 
                   
                     
                       H 
                        
                       
                         ( 
                         s 
                         ) 
                       
                     
                     = 
                     
                       
                         Y 
                          
                         
                           ( 
                           s 
                           ) 
                         
                       
                       
                         X 
                          
                         
                           ( 
                           s 
                           ) 
                         
                       
                     
                   
                    
                   
                     
 
                   
                    
                   
                     
                       X 
                        
                       
                         ( 
                         s 
                         ) 
                       
                     
                     = 
                     
                       
                         ℒ 
                          
                         
                           { 
                           
                             x 
                              
                             
                               ( 
                               t 
                               ) 
                             
                           
                           } 
                         
                       
                        
                       
                         = 
                         def 
                       
                        
                       
                         
                           ∫ 
                           
                             - 
                             ∞ 
                           
                           ∞ 
                         
                          
                         
                           
                             x 
                              
                             
                               ( 
                               t 
                               ) 
                             
                           
                            
                           
                              
                             
                               - 
                               st 
                             
                           
                            
                           
                               
                           
                            
                           
                              
                             t 
                           
                         
                       
                     
                   
                    
                   
                     
 
                   
                    
                   
                     
                       Y 
                        
                       
                         ( 
                         s 
                         ) 
                       
                     
                     = 
                     
                       
                         ℒ 
                          
                         
                           { 
                           
                             y 
                              
                             
                               ( 
                               t 
                               ) 
                             
                           
                           } 
                         
                       
                        
                       
                         = 
                         def 
                       
                        
                       
                         
                           ∫ 
                           
                             - 
                             ∞ 
                           
                           ∞ 
                         
                          
                         
                           
                             y 
                              
                             
                               ( 
                               t 
                               ) 
                             
                           
                            
                           
                              
                             
                               - 
                               st 
                             
                           
                            
                           
                               
                           
                            
                           
                              
                             t 
                           
                         
                       
                     
                   
                    
                   
                     
 
                   
                    
                   
                     
                       x 
                        
                       
                         ( 
                         t 
                         ) 
                       
                     
                     = 
                     
                       
                         X 
                          
                         
                             
                         
                          
                         
                            
                           
                             j 
                              
                             
                                 
                             
                              
                             ω 
                              
                             
                                 
                             
                              
                             t 
                           
                         
                       
                       = 
                       
                         
                            
                           X 
                            
                         
                          
                         
                            
                           
                             j 
                              
                             
                               ( 
                               
                                 
                                   ω 
                                    
                                   
                                       
                                   
                                    
                                   t 
                                 
                                 + 
                                 
                                   arg 
                                    
                                   
                                     ( 
                                     X 
                                     ) 
                                   
                                 
                               
                               ) 
                             
                           
                         
                       
                     
                   
                    
                   
                     
 
                   
                    
                   
                     
                       y 
                        
                       
                         ( 
                         t 
                         ) 
                       
                     
                     = 
                     
                       
                         Y 
                          
                         
                             
                         
                          
                         
                            
                           
                             j 
                              
                             
                                 
                             
                              
                             ω 
                              
                             
                                 
                             
                              
                             t 
                           
                         
                       
                       = 
                       
                         
                            
                           Y 
                            
                         
                          
                         
                            
                           
                             j 
                              
                             
                               ( 
                               
                                 
                                   ω 
                                    
                                   
                                       
                                   
                                    
                                   t 
                                 
                                 + 
                                 
                                   arg 
                                    
                                   
                                     ( 
                                     Y 
                                     ) 
                                   
                                 
                               
                               ) 
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                      
                     
                         
                     
                      
                     2 
                   
                   ] 
                 
               
             
           
         
       
     
     (|X| (represents an amplitude, ω represents an angular frequency, and arg(X) and arg(Y) represents a phase) 
     The control unit  140  transforms the noise spectrum of the target  200  detected by the microphone  130 - 5  shown in  FIG. 4A  into the compensation spectrum according to the replacing acoustic information as shown in  FIG. 4B  by using the acoustic compensation algorithm including the transfer function H. 
     After transforming the detected noise information into the compensation spectrum according to the replacing acoustic information, the control unit  140  determines whether the spectrum G jj     A   (f) according to the replacing acoustic information has a value larger than the spectrum of the transfer function H ij  from the target  200  to the noise detector (microphone) in the anechoic room in accordance with the related art (S 340 ). 
     If it is determined that the spectrum G jj     A   (f) according to the replacing acoustic information has a value larger than the spectrum of the transfer function H ij  from the target  200  to the noise detector (microphone) in the anechoic room, the control unit  140  defines the spectrum G jj     A   (f) according to the replacing acoustic information as an evaluation criterion for evaluating the pure tone of the target  200  (S 350 ). 
     On the other hand, if it is determined that the spectrum G jj     A   (f) according to the replacing acoustic information has a value equal to or smaller than the spectrum of the transfer function H ij  from the target  200  to the noise detector (microphone) in the anechoic room, the control unit  140  makes the value of the spectrum G jj     A   (f) according to the replacing acoustic information and the value of the spectrum of the transfer function H ij  from the target  200  to the noise detector (microphone) in the anechoic room equal to each other (S 342 ). 
     For example, as a result of comparing the spectrum G jj     A   (f) according to the replacing acoustic information shown in  FIG. 4B  with the spectrum of the transfer function H ij  from the target  200  to the noise detector (microphone) in the anechoic room shown in  FIG. 5 , these spectrum waveforms are similar to each other or have insignificant difference or are the same as each other. Therefore, the control unit  140  may equalize the value of the spectrum shown in  FIG. 4B  and the value of the spectrum shown in  FIG. 5  as the same spectrum as each other. 
     Therefore, the control unit  140  uses the equalized spectrum as an evaluation criterion for evaluating the pure test one of the target  200  (S 344 ). 
     As described above, the pure tone evaluation of the target is performed by the prominence ratio (PR) value calculated by using the equalized spectrum defined at S 344  or the spectrum G jj     A   (f) according to the replacing acoustic information defined at S 350  as the evaluation criterion for evaluating the pure tone of the target  200  (S 360 ). 
     Here, the pure tone evaluation of the target  200  by the PR value may be largely classified into two evaluation methods, that is, a method using a critical band and a method using octave analysis. 
     The method for evaluating the pure tone using the critical band may calculate a difference value in average values of sound pressure levels at the critical band of both sides of the target  200  represented by “A” and “C” for the sound pressure level of the critical band including the pure tone component of the target  200  represented by “B” as the PR value in the spectrum of the evaluation criterion shown in  FIG. 4B . 
     For example, in  FIG. 4B , the sound pressure level of the critical band of 3.24 KHz including the pure tone component of the target  200  represented by “B” is 10 dB and the average value of the sound pressure levels at the critical band of both sides thereof represented by “A” and “C” is −23 dB, such that the PR value of the target  200  is calculated as 33 dB. The PR value of 33 dB, which is a high numerical value corresponding to the noise level in which the pure tone of the target  200  is out of an allowable PR range, may evaluate the pure tone of the target  200  as a defect. 
     In this case, the allowable PR range for evaluating the pure tone of the target  200  may be different according to the device of the target  200 . 
     Unlike this, the control unit  140  may calculate the continuous PR value by ⅓ octave analysis or 1/12 octave analysis so as to evaluate the pure tone at a low frequency domain less than 1 KHz. 
     The octave analysis is one of the frequency analysis methods that pass through the measured time signals in 33 frequency bands and calculate the PR size. For example, a ⅓ octave band exponentially divides again a section of a start frequency and a terminal frequency that is two times higher than the start frequency in a band, like 500 Hz to 1000 Hz and 1000 Hz to 2000 Hz, into three sections. 
     Therefore, the ⅓ octave analysis is a method of analyzing the PR value by using a frequency band having the relatively narrow frequency interval in the case of the low frequency and the relatively wide frequency interval in the case of the high frequency. Further, the 1/12 octave analysis exponentially divides the start frequency and the terminal frequency that is two times higher than the start frequency into 12 sections to analyze the PR value in each frequency band. 
     Therefore, the method for controlling a pure tone test apparatus for performing the pure tone evaluation of the target  200  in accordance with another preferred embodiment of the present invention calculates and analyzes the PR value for the spectrum obtained by transforming the detected noise from the target  200  according to the acoustic algorithm to easily perform the pure ton evaluation of the target  200 . 
     The pure tone test apparatus in accordance with the preferred embodiments of the present invention can easily perform the pure tone evaluation of the target using the PR value calculated by transforming the detection noise of the target according to the acoustic algorithm without performing the pure tone evaluation in the expensive anechoic room in accordance with the prior art. 
     Although the embodiments of the present invention have been disclosed for illustrative purposes, it will be appreciated that the present invention is not limited thereto, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. 
     Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims.