Welcome to the KNOWLES Measuring the Frequency Response of Balanced Armature Drivers and Earphones product training module. This presentation will discuss the general characteristics of the different measurement methods, the advantages and limitations of each, and how each are best interpreted in trying to understand an earphone’s frequency response. A special section will discuss one way of measuring an earphone’s response to 40 kilohertz (kHz) for the JAS Hi Res Audio initiative.