 Over the next twenty-five years, Villchur's innovations became the industry standard for hearing aid design.It is nearly impossible to find a hearing aid today – digital or analog – that does not use multi-channel wide dynamic range compression.Edgar Villchur has written three books and over one hundred and fifty articles on high fidelity, sound reproduction, audio engineering, and hearing aid technology in both peer-reviewed scientific journals and popular magazines, including two articles written when he was ninety years old.