New technique better detects hearing loss

A new technique to diagnose hearing loss in a way that more accurately reflects real-world situations is being worked on by a researcher from Purdue University, West Lafayette, Ind.

"The traditional method to assess speech understanding in people with hearing loss is to put them in a quiet room and ask them to repeat words produced by one person they can't see," explains Karen Iler Kirk, professor of speech, language and hearing sciences.

"The goal of our research is to develop new tests that reflect more natural listening situations with visual cues, different background noises, voice quality, dialects, and speaking rates. This is a more accurate way to predict how people perceive speech in the real world and, therefore, can help us determine appropriate therapy and interventions, such as cochlear implants."

Kirk is developing two new audiovisual and multitalker sentence tests that expand upon the traditional word recognition format that has been used since the 1950s. One test is for adults and the other for children. "The traditional spoken word recognition format has been used to determine the need for some sensory aids, such as hearing aids, which are used to amplify sound," Kirk explains. "However, it is not the best method for assessing the benefits of other sensory aids, such as the more expensive cochlear implants."

[ILLUSTRATION OMITTED]

A cochlear implant is an electronic device that can provide a sense of sound to someone who is deaf or severely hard of hearing. It is implanted surgically and picks up and processes sound that is converted into electric impulses that are sent to the auditory nerve. More than 100,000 people worldwide have received them, and more health insurance companies are paying for the surgery and therapy.

This project also is expanding word lists from the traditional monosyllabic ones to a greater range based on how often they are used and lexical density--the number of words phonetically similar to the target. For example, "cat" has a number of lexical neighbors such as "bat," "cap," "cut," and "scat." A word like "banana" may be used frequently, but has few words that sound similar.

The 10 diverse speakers, who are recording more than 6,000 sentences combined, purposely will not be producing perfectly articulated speech. "It's important to use sentence materials that are produced by different speakers because, in the real world, we do not listen to just one person," Kirk notes.

In addition to the auditory component, the materials will be presented in a visual format so listeners can see and hear the phrase. "This is really important because hearing-impaired people often have great difficulty understanding speech if they are just listening. Seeing the face and following lip reading cues can help someone understand the intended message."

COPYRIGHT 2008 Society for the Advancement of Education
COPYRIGHT 2008 Gale, Cengage Learning