Some fans do not sound very loud, yet they may still feel sharp, buzzing, or annoying over time. Others can run continuously without drawing much attention. This difference is not determined by decibels alone. It is also related to frequency distribution, tonal components, loudness, sharpness, roughness, and fluctuation strength. Using fan noise as an example, [...]

In motor, headphone, speaker, and complete product testing, anomalous sound is often not a simple sound pressure level issue. Many early defects appear as slight rubbing noise, whistling, buzz, anomalous noise, or changes in spectral details. Traditional electroacoustic testing and manual listening inspection are difficult to keep consistent in large-scale testing. Using TWS earbud AI [...]

Using a wired headphone acoustic measurement workflow as an example, this article explains how OpenTest connects to an NI USB-4431 DAQ device and supports a complete acoustic test workflow, from test setup, channel configuration, and signal acquisition to frequency response analysis, distortion analysis, report generation, and sequence-based automation. The workflow helps engineering teams upgrade their [...]