 Unlike the previous "compression limiting" circuits, which limited loud sounds to a certain level but did nothing to increase the gain for quiet sounds, Villchur's WDRC amplifiers increased gain for softer sounds without excessively amplifying louder sounds.Rather than apply for a patent, he decided to publish his findings and make them freely available.Fred Waldhauer of Bell Labs heard Villchur lecture on this new hearing aid system, and started a Bell Labs project to develop a hearing aid.