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Description
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Technote 142 discusses testing the audio performance of USB headsets with APx500 Series audio analyzers using open-loop test techniques. The discussion specifically illustrates measuring the frequency response magnitude of a headset’s microphone and earphones using the log-swept sine (chirp) method.
It is worth noting that although TN142 focuses on frequency response measurement, the same open-loop test techniques covered can be used in APx to measure a range of audio quality metrics including noise, level, gain, harmonic distortion, intermodulation distortion, interchannel phase, speech quality, etc. In addition, other methods of measuring frequency response are available, including classic swept sine, multitone analysis and transfer function measurements (using noise, music or speech as a stimulus).
Note: An APx project file (named “USB Headset.approjx”) that implements the tests on typical hardware is included in this download. |
