The "hearing-glasses", like the company, are called Varibel. To capture and relay sound to the ears microphones, signal processing and miniature speakers are contained in the arms of the frames.

The hearing-glasses were originally developed at Delft University of Technology in the Netherlands. Varibel developed these glasses into a consumer product in partnership with Royal Philips Electronics, a vendor of frames for glasses called Frame Holland and the design agencies MMID and Verhoeven. The hearing-glasses are due to go on sale at Beter Horen audio shops in The Netherlands from mid April, the university said.

Many people aged over 60 use hearing aids to try and help cope with old-age hearing loss. However, with the loss of high-frequency discrimination simple amplification is not always beneficial.

Many hearing aids intensify sounds from all directions and it is not always possible to hear others well if there is surrounding noise. A frequent complaint is that hearing aids often just make confusing noise louder and more annoying.

Solutions to this problem, tried with in-ear digital hearing aids, include multi-microphone systems that provide tunable directionality so that a hearing aid has a preferred direction of sensitivity, usually tuned to be forward facing. In this way the hearing aid increases the sound from a conversation ahead of the user but reduces background noises.