Beats sued by Bose over noise-cancelling patents
Headphones-maker Beats Electronics is being sued by rival Bose over its range of noise-cancelling audio gear.
Massachusetts-based Bose claims that Beats has infringed five of its patents.
Bose alleges it has lost sales to its competitor as a consequence. Beats declined to comment.
The legal action comes two months after Apple announced it was buying Beats for $3bn (£1.8bn) - its largest acquisition to date.
One expert said it was not unusual for takeovers to prompt such litigation.
"It's not uncommon, because when companies are in the process of being taken over they don't want the uncertainty of litigation," said Ilya Kazi from the UK's Chartered Institute of Patent Attorneys.
"So, they are more likely to be inclined to settle. It's a good time to apply leverage."
The European Union's competition watchdog approved the deal this Monday.
Active noise reduction
The disputed patents have been listed on the Prior Smart patent news site.
Bose was granted the rights to the inventions over a nine-year period ranging from 2004 to 2013.
They all centre on the privately-owned company's development of a technique called active noise reduction (ANR).
"ANR is a technique to reduce unwanted noise by introducing a second sound source that destructively interferes with the unwanted noise," explained Bose's lawyers, Shaw Keller, in documents filed with Delaware District Court.
"ANR headphones typically use at least one microphone to detect unwanted ambient noise, and the headphone speaker produces soundwaves of reverse phase to destructively interfere with the unwanted sound."
They go on to explain that the company originally developed the tech for the US Air Force and US Army, before launching its first noise-cancelling headphones for consumers in 2000.
The lawyers added that Beats had failed to license Bose's tech despite being informed that it was infringing its intellectual property.
"Bose's continued success depends in substantial part on its ability to establish, maintain, and protect its proprietary technology through enforcement of its patent rights," they state.
Beats' site markets its adaptive noise-cancelling feature as the ability to "put the world on mute" on the web pages of its Studio range of headphones.
The feature is fairly common among premium earbuds and headphones with JVC, Sennheiser, Sony and Harman Kardon among other companies to offer the facility.
"Our patents cover our unique approach to active noise cancellation," Carolyn Cinotti, director of public relations at Bose.
"Other companies may have their own unique approach. We don't license our technology to other headphone manufacturers."