Method and apparatus for checking an acoustic test fixture

Abstract

A body has a first portion whose exterior surface is similar to that of a corresponding, first portion of a portable media device. An acoustic aperture is formed at a location that is similar to that of a built-in earpiece, speaker, or microphone aperture in the media device. An acoustic port is formed in the exterior surface of the body, and is adapted to be coupled to a sound test tool. An internal cavity acoustically couples the acoustic port to the acoustic aperture. Other embodiments are also described and claimed.

1 . A method for checking a test fixture, the test fixture to be used for acoustic testing of a portable media device under test (DUT), the method comprising:
 a) installing a calibrator device to cooperate with the test fixture, the calibrator device having a portion whose exterior shape and dimensions mimic those of a corresponding portion of the DUT so that the calibrator device fits with the test fixture in the same way as the DUT;   b) coupling an acoustic input or acoustic output port of a sound test tool to an acoustic port of the calibrator device, the calibrator device having an internal cavity that acoustically couples the acoustic port to an acoustic aperture on its exterior surface, the acoustic aperture of the calibrator device being aligned with an acoustic aperture of the test fixture for acoustic coupling purposes; and   c) measuring a sound test signal that propagates through the test fixture, through the internal cavity of the calibrator device, and through the acoustic apertures of the calibrator device and the test fixture.   
     
     
         2 . The method of  claim 1  further comprising:
 making a plurality of sound test signal measurements as per c), using the same calibrator device as applied to a plurality of test fixtures, respectively; 
 comparing the plurality of sound test signal measurements; and 
 determining which ones of the plurality of test fixtures need adjustments, based on the comparing. 
 
     
     
         3 . The method of  claim 1  wherein in b), said coupling comprises connecting an output sound port of a reference sound pressure source to the acoustic port of the calibrator device, the method further comprising:
 coupling a sound pressure level meter to an acoustic port of the test fixture that is acoustically coupled by the test fixture to the acoustic aperture that is aligned with the calibrator device. 
 
     
     
         4 . The method of  claim 1  wherein in b), said coupling comprises connecting an input sound port of a sound pressure level meter to the acoustic port of the calibrator device, the method further comprising:
 coupling a reference sound pressure source to an acoustic port of the test fixture that is acoustically coupled by the test fixture to the acoustic aperture that is aligned with the calibrator device. 
 
     
     
         5 . A method for checking a test fixture, the test fixture to be used for acoustic testing of a cellular telephone handset under test (DUT), the method comprising:
 a) installing a calibrator device to cooperate with the test fixture, the calibrator device having a portion whose exterior shape and dimensions mimic those of a corresponding portion of the DUT so that the calibrator device fits with the test fixture in the same way as the DUT;   b) coupling an acoustic input or acoustic output port of a sound test tool to an acoustic port of the calibrator device, the calibrator device having an internal cavity that acoustically couples the acoustic port to an acoustic aperture on its exterior surface, the acoustic aperture of the calibrator device being aligned with an acoustic aperture of the test fixture for acoustic coupling purposes; and   c) measuring a sound test signal that propagates through the test fixture, through the internal cavity of the calibrator device, and through the acoustic apertures of the calibrator device and the test fixture.   
     
     
         6 . The method of  claim 5  further comprising:
 making a plurality of sound test signal measurements as per c), using the same calibrator device as applied to a plurality of test fixtures, respectively; 
 comparing the plurality of sound test signal measurements; and 
 determining which ones of the plurality of test fixtures need adjustments, based on the comparing. 
 
     
     
         7 . The method of  claim 5  wherein the coupling of the acoustic input or output port comprises:
 coupling the acoustic output port of a reference sound pressure source to the acoustic port of the calibrator device.