Microphones & Mic Arrays
Simultaneous, Multichannel Measurements
The rapid adoption of “smart devices”-with smartphones and smart speakers leading the way—has made MEMS microphones (mics) ubiquitous to everyday life. The heart of any smart device is the Intelligent Virtual Assistant (IVA), enabling the use of voice commands to direct the device to do everything from playing audio content to providing a weather forecast and these voice commands are acquired via the integrated MEMS microphone or, more likely, an array of such mics.
Micro-electromechanical system (MEMS) mics are extremely small mics that are used in a wide range of applications and use a pulse density modulation (PDM) stream as their digital output. MEMS mics are integral components in a wide range of products and systems, including hearing aids, mobile computing, automotive and IOT systems.
The use of multiple mics in a smart device can provide distinct benefits to the end product—for example, using multiple mic inputs for improved signal-to-noise ratio (SNR). It also complicates the testing process used to evaluate and characterize designs owing to the need for simultaneous, multichannel measurements. Additionally, engineers developing systems using beamforming mic arrays, and other DSP-based multichannel audio acquisition applications, depend on a true representation of phase alignment of the input channels to validate their algorithms and designs.
PDM 16 Input Module
Acoustic test is challenging and trying to measure the acoustic performance of a MEMS mic array can be especially daunting with the added requirement of validating phase alignment. The PDM 16 module, designed for the APx Series modular audio analyzers, provides the ability to incorporate all of the APx analyzer capability with your MEMS testing. This module provides 16 acquisition channels and can provide simultaneous analysis of all 16 channels on a single screen.