TLB GmbH Background
Headphones are small loudspeakers worn on or around the head covering the user’s ears. They allow an individual user to listen to sounds privately, as opposed to a loudspeaker that radiates sounds to anyone nearby. Headphones are electroacoustic transducers that convert an electrical signal into a corresponding sound. As a result of the Walkman effect, headphones began to be used in public places such as sidewalks, grocery stores, and public transportation in the 1980s and are now widely used in the public.
The global market for headphones was worth around USD 25 billion in 2019 and is expected to continue to grow rapidly in the coming years at a compound annual growth rate (CAGR) of about 20%. It is also assumed that consumers’ increasing preference for stylish, attractive designs in particular will also boost sales.
When wearing headphones and playing a sound such as music, the auditory detection ability of the surroundings of the wearer is significantly limited. It is difficult or even impossible to distinguish whether an external sound source approaches from the front or back, i.e. the so called front-back confusion. That may cause dangerous situations for traffic, for example a vehicle approaching in the back of the wearer may not be detected.
Technology Overview
Similar to the human auditory system, the innovative filtering element is arranged on the outer surface of the headphone around the microphone input and enables the processing and integration of external sound signals at the ears of the wearer and thus the disambiguation of sounds from different directions, in particular from vertical directions, regardless of their spectral composition. Thus, the outer surface of the filter element is provided with specifically shaped structures, i.e. protrusions, which modify the spectral composition of the external sound in such a way as to produce frequency modulations depending on their spatial position. These resulting ´artificial´ head-related transfer functions allow precise localization of external sound source in the vertical plane and resolution of disambiguations resulting from horizontal localization features, i.e. front-back confusion. Thus, any auditory object in the environment of the wearer can be precisely localized, especially auditory objects in the ´blind spot´ of the wearer.
Benefits
Headphones avoid the so called front-back confusion
sound sources in the wearer’s `blind spot´ can be precisely localized
different designs of the filtering element/shaped structures are possible
designed for more safety in public situations especially in traffic
Applications
Improvement of headphones, earspeakers, earphones or, colloquially, cans, circumaural (‘around the ear’), supra-aural (‘over the ear’) headphones and also in- ear headphones, earbuds, earpieces, headsets or bone conduction headphones to avoid the so called front-back confusion.