Leo L. Beranek, an engineer whose company designed the acoustics for the United Nations and concert halls at Lincoln Center and Tanglewood, then built the direct precursor to the internet under contract to the Defense Department, died on Oct. 10 at his home in Westwood, Mass. He was 102.

His death was confirmed by his son James.

Dr. Beranek taught acoustic engineering at Harvard and M.I.T. for more than three decades after World War II, conducting research there that laid the groundwork for acoustic advances with wide social impact, including noise standards for public buildings and airports. But one of his most notable achievements was well outside the field of acoustics.

In 1969, the company he helped found, Bolt, Beranek & Newman, won a contract from the Defense Department’s Advanced Research Projects Agency to build the first computer-based network, which came to be called Arpanet.

By demonstrating the ability to share data and messages through vast computer networks, Arpanet, a product of government-sponsored research, paved the way for the creation of the internet. Among its many breakthrough achievements, his company sent the first email message that used the @ symbol, in 1972.