ECMs and MEMS Microphone Test

At PUI Audio, microphone characterization is a critical part of our product development and validation process. Using world-class acoustic measurement systems, calibrated reference instruments, controlled acoustic environments, and standardized test methodologies, we generate accurate and repeatable data that enables confident evaluation of microphone performance.
Our testing capabilities support product development, supplier qualification, design validation, root-cause analysis, and production quality assurance, allowing customers to make informed design decisions with confidence.

Measuring Microphone Performance
This document describes the procedure for characterizing microphone performance using standardized acoustic test methods and calibrated measurement equipment. The methodology is applicable to both Electret Condenser Microphones (ECMs) and MEMS Microphone technologies.

The methodology utilizes an anechoic or acoustically isolated environment, along with specialized software and laboratory-grade hardware, to establish a stable and traceable acoustic reference. A known sound source, typically a speaker generating a swept sine or controlled tones across the desired frequency range, is used in conjunction with a calibrated reference microphone to accurately measure sound pressure levels and compensate for system and environmental variations.

Prior to testing, both the reference microphone and acoustic source are calibrated at 94 dB SPL to ensure measurement accuracy and traceability. The device under test is then powered using a regulated DC bias supply with appropriate impedance, ensuring correct electrical operation and signal integrity, while sensitivity settings are configured for proper data acquisition. The output of the microphone is recorded and compared against the reference to determine key performance characteristics such as sensitivity, frequency response, and consistency. This structured methodology ensures reliable, repeatable results that reflect true device performance and is specifically applied to testing both ECMs and MEMS microphone technologies.

In addition to sensitivity and frequency response measurements, the Listen SoundCheck® platform supports advanced microphone characterization capabilities including self-noise, Signal-to-Noise Ratio (SNR), Total Harmonic Distortion (THD), and Acoustic Overload Point (AOP) testing. These capabilities enable comprehensive evaluation of microphone performance across a wide range of applications.