Another step toward aiding the partially deaf to hear perfectly has been taken in the Psycho-Acoustical Laboratory of the University in the basement of Memorial Hall.

Ira J. Hirsh, research fellow in Acoustics, has developed a now hearing aid that enables the user to perceive and place the distance of sounds as if he had normal hearing.

The aid consists of two small but complete microphone and amplifier units that attach directly to each ear, giving the advantage of binatural perception. Standard devices have only one mike to pick up sounds, usually the size of a package of cigarettes, and one amplifier behind the ear.

Two-Ear Set

Some companies manufacture a set that has amplifiers on both ears, but still only one mike, thus acting like one ear transmitting sounds to both auditory lobes in the brain. Under this system, all sounds seem to come from the same place and the listener cannot tell where to direct his attention.

"The disadvantages of nonaural hearing become apparent in a lecture hall or cocktail lounge," explained Hirsh. "The listener never knows who is speaking." Using this new aid, sounds from the right will be perceived a fraction of a second earlier in the right unit than in the left, enabling the user to tell from what direction they are coming. This is the principle on which normal hearing operates.

Big Devices

Although the results of Hirsh's experiments have been published, no companies have shown any interest yet. "They probably object to the idea because of the appearance angle," commented the inventor. The devices are each 3/4 inch square.

However, he did discover that the plan had been patented before, in 1912.

The Pscho-Acoustical Laboratory operates on a budget from the University and grants from the Office of Naval Research. Hirsh is presently working on the cause and cures of temporary deafness, resulting from loud noises or shocks, and its relation to permanent deafness.