Tribute to An Industry Pioneer: Gunnar Rasmussen (1925-2024)

The founder of GRAS Sound & Vibration, the renowned acoustical engineer Gunnar Rasmussen, passed away on April 17, 2024. Gunnar Rasmussen founded GRAS in 1994, at the age of 67, after leaving Brüel & Kjær, where he worked since his graduation. Starting out as a small family business, run by Gunnar Rasmussen and his wife Hanna Hertz, the Danish measurement microphones specialist quickly grew into a respected manufacturer, lead by his extraordinary vision and guiding principles. His lifework improved our understanding of sound, acoustics and the human hearing.

With the availability of the HEL/HER 4.4 ViBRIDGE Flexible Pinna for HMS II.3/5, the industry as gained a vital testing tool for in-ear headset designs that utilize bone conduction sensors. Evaluating these systems is vital to optimize near-end structure-borne sound to improve speech quality in the presence of background noise, improve echo cancellation, and double-talk performance. The unique technology developed by HEAD acoustics is being enthusiastically embraced by the industry.

Voice Coil June 2023 features an extensive patent review in James Croft's Acoustic Patents column. The topic is a 2014 patent awarded to Nokia, offering an opportunity to revisit the history of electrostatic loudspeakers, with insights from Tim Mellow, one of the two listed inventors. In Test Bench, Vance Dickason focuses on the D8404-552000 Ellipticor cloth diaphragm dome midrange from Scan-Speak, and characterizes the SB Acoustics TW29BNWG beryllium dome and waveguide from the brand's prestigious Satori line.

As many audioXpress readers already learned from reading the article by Hans W. Gierlich on the Benefits of Using Structure-Borne Sound in Headset Signal Processing, HEAD acoustics created a complete test solution for in-ear and headset devices using bone-conduction sensors. There are good reasons for developers and manufacturers to explore the use of bone-conduction sensors and test them with the new ViBRIDGE solution.

HEAD acoustics succeeded in the standardization of the newly developed artificial ear with human-like ear canal (HEC). The new artificial ear is now standardized as Type 4.4 artificial ear in Recommendation ITU-T P.57. The HEAD acoustics HEC artificial ear not just fulfills the Type 4.4 artificial ear requirements, it is also the first ITU-T standardized artificial ear meeting the low-noise requirements for artificial ears as defined in the new chapter 7 of Recommendation P.57.

HEAD acoustics introduced a new and much improved design for its artificial heads paving the way for new era of communication and audio quality measurements. The new generation of artificial heads ensures a new level of realism, precision and flexibility when coupled with HEAD acoustics modular concept approach, meeting the most diverse of applications in the field of acoustic measurement technology.