Earphone testing software speeds development

Audio test and measurement provider Audio Precision unveils a software utility that automates testing of headphones and earphones used with portable audio players. The utility runs on Audio Precision's APx Series analyzers to automate the measurements required by British Standard/European Norm 50332 Parts 1 and 2, thus cutting development time.

The accompanying new AP Technote "Measuring the Sound Pressure Level of Portable Audio Player Headphones with APx Audio Analyzers" describes in detail how to use the utility to conduct the tests specified in the standard.

The standard requires a special Program Simulation Noise test signal and a test fixture known as a Head and Torso Simulator. Sound pressure levels measured in the ear simulators of the HATS must be corrected to free field response and then A-weighted and averaged.

"The calculations needed to derive the results required by the standard are too complex for the typical user to do manually," says Joe Begin, head of AP's Technical Support. "And the Program Simulation Noise signal would also be a challenge for customers. We used Matlab to create the signal in the digital domain. The utility bundles that in and takes care of all the necessary calculations."