The Acoustical Challenges of Designing True Wireless Earphones

Expanding the perspective on the evolution toward hearables, this article explores the current trends as well as the acoustical challenges and solutions for designing true wireless earphones. The article explains the enabling technologies currently converging as the TWS market continues to grow and use cases multiply, with more consumers using wireless earbuds for a diverse and varied set of applications, from listening to podcasts and audiobooks to Internet meetings and interacting with voice assistants. This article was originally published in audioXpress, April 2022.

A new Preferred Listening Response Curve that could define the next standard in high-resolution earphones, was the result from a new research by Knowles Corporation. The research is intended to guide product designers, and reflects the findings of an internal effort by the balanced armature manufacturer to determine the best and most satisfying music listening experience for consumers. In the research report, Knowles proposes an evolution of the Harman response curve specific to in-ears that takes into consideration frequencies above 10kHz

Voice Coil January 2019 is now available. This edition focuses on New Materials for Earphones and Headphones and also includes a valuable listing of Earphone and Headphone Manufacturers and a schedule of headphone-centric events for the year. In Acoustic Patents, James Croft looks at a new patent of a multilayer voice coil plate and flat speaker based on the same, while in this month's Test Bench Vance Dickason features a 1" compression driver from Radian Audio Engineering, and a 1" soft dome tweeter from Eminence. This is much more, now available in print and download.

GRAS Sound & Vibration, the world-renowned manufacturer of high quality measurement microphones and related acoustic equipment, announced the availability of a new, High Resolution Ear Simulator designed specifically to meet the need for reliable and repeatable measurements of personal audio devices at high frequencies. An ideal solution for development of in-ear as well as supra- and circumaural headphones.

STMicroelectronics and Austrian company USound GmbH announced their collaboration on the industrialization and production of the world's first miniature piezoelectric MEMS (Micro-Electro-Mechanical Systems) actuators for smart audio systems in portable devices. The patented micro-speaker technology from USound aims to replace commonly used balanced-armature and electrodynamic receivers for handsets with a small piezo-MEMS actuator.

Knowles Corporation launched the new RAF Series balanced armature drivers to improve how hearable and earphone designers create the next generation of premium headsets. Developed for wireless products, the receiver’s small dimensions and high efficiency make it ideal for a number of applications. The new RAF Series, including IPx7 models, enables greater flexibility to improve critical features such as audio quality, connectivity, battery life, and water resistance without sacrificing size or comfort.