Vigo County Historical Society

Historical Treasure Article

Historic Treasure of the Week - January 12, 1986
By Deborah Curtis
Vigo County Historical Society

Lend an ear
Device captured sound pressure waves

When President Reagan holds a televised press conference, few viewers notice the tiny hearing aid he wears. Had Reagan been president 150 years ago, however, his hearing impairment would have been much more obvious to the public. He probably would have used a device similar to this week's historical treasure--a tin ear trumpet, circa 1820.

According to information provided by the Vigo County Public Library, the ear trumpet was invented between 1650 and 1700.

The way it works is simple. Sound pressure waves enter through holes in the large bell end of the trumpet. As the sound waves travel into and through the narrower tube, they are condensed into smaller and smaller waves, increasing the sound wave pressure into the ear. The degree of pressure increase depends only on the relative sizes of the large and small openings. Recent experiments by staff and friends of the Historical Museum of the Wabash Valley, 1411 S. Sixth St., led to the conclusion that the ear trumpet does indeed amplify sound. Even more apparent, however, is the change in sound quality, which might best be duplicated by talking to oneself while leaning into a steel drum.

While the ear trumpet in the collection in the museum looks simple, it is actually constructed of eight separate pieces of tin soldered together. The tube is in two sections which can be separated, probably to allow ease of transport. A brass wire serves as a lock to hold the two parts of the tube together. The overall length of the trumpet is 21 1/2 inches. The bell opening is 5 1/2 inches in diameter.

With the invention of the first electronic hearing aid around 1900 (the result of Alexander Graham Bell's experiments in developing the telephone), followed closely by further refinements in hearing aid methods, the ear trumpet probably passed out of common use by the 1920s.

The ear trumpet in the museum originally was owned by Mary E. Stader. It was donated to the museum by her granddaughter, Mrs. C. E. Rippetoe, in 1961.

The Historical Museum of the Wabash Valley, 1411 S. Sixth St., is open from 1 to 4 p.m. Sunday through Friday.