Use of FM Technology to Improve Telephone Communication: A Case Study

The ability to communicate on the telephone is often fundamental to an individual’s independence. Without this ability, individuals must rely on spouses, family members, or neighbors to make and receive telephone calls on their behalf. Patients with severe to profound hearing loss have considerable difficulties understanding speech on the telephone, even when using a hearing aid telecoil. In this article, I report data from an individual who participated in a study to examine the effectiveness of frequency modulation (FM) technology for adults with significant hearing loss. During the study, many participants identified improved telephone communication to be a major goal of rehabilitation. For this reason, we began to dispense devices that transmit the telephone signal to listeners’ behind-the-ear (BTE) FM receivers, allowing the listener to hear the telephone signal in both ears at an appropriate level. For the study, participants were seen for an initial evaluation at which time they completed study test measures and their FM devices were ordered. Two weeks later, participants were fit with the devices and a TelCom system (Phonak Hearing Systems, Inc., Chicago, IL) (described later in this article) if improved telephone use was identified as a goal of rehabilitation. At that time, they also were provided extensive individualized counseling on use of the FM system in listening situations they reported as troublesome with their hearing aids. Each participant was then seen for three further visits that occurred at two-weekly intervals. At the last of their visits, subjects completed the study test measures a second time. The study test measures were the Client-Oriented Scale of Improvement (COSI),[1] a modified MarkeTrak VI survey,[2] and questions from the Communication Profile of the Hearing Impaired (CPHI)[3] that comprise the Communication Performance subscale.

The individual is a 66-year-old male who first experienced hearing loss in the early 1970s. At that time he was told “hearing aids would not help with his type of nerve damage.” In 1986 when he was teaching at the college level, his hearing had deteriorated to the point that he had difficulty functioning in the classroom as well as on the telephone and in social situations. He purchased his first hearing aids at that time. He has since experienced continued deterioration of his hearing over the past 17 years and is wearing his sixth pair of hearing aids. Figure [1] shows his current audiometric configuration.

Figure 1 Current audiogram of the study participant. X, left ear air conduction thresholds; O, right ear air conduction threshold.

This individual currently uses analog, digitally programmable, wide dynamic range, two-channel BTE hearing aids and operates them with a remote control. For the study, he was fit with a Phonak Microlink system (Phonak Hearing Systems, Inc., Chicago, IL), including FM receivers that attach to the bottom of the BTEs, a handheld microphone transmitter, and a TelCom (telephone) transmitter. He did not receive the TelCom at the start of the study because initially he did not indicate that communication on the telephone was of high priority. However, after using the FM system for a couple of weeks, he realized that he might be able to raise his expectations regarding his ability to communicate by telephone. At this point a TelCom system was dispensed.

The TelCom is an FM transmitter that connects to both telephone and audio signals, such as the television and the radio. When the FM system is in use with an audio input, the TelCom sends the telephone ring through the FM system to the hearing aid. When the user answers the telephone, TelCom automatically mutes the audio input and transmits the telephone signal through the system. The volume of the television or radio is not altered for others in the room. When the telephone handset is replaced, the audio input is turned back up to the previous volume setting. If the user answers the phone but the call is intended for someone else, the user can override the TelCom and re-engage the audio signal allowing the phone user to talk on the telephone privately. The TelCom has an operating range of 23 to 50 feet.

The results presented below relate to the individual’s telephone use. First, anecdotal reports highlight how impressed the individual was with the TelCom. He reported that he was able to use the telephone again. He had given up trying to use the telephone because it was too hard for him to comprehend the incoming signal. He reported that the TelCom had solved this problem completely. Below are some of his comments regarding the TelCom device:

“The equipment has already (in 6 weeks) improved the quality of my life significantly.”

“I also spent some time today and this evening on the telephone. What a treat it is to actually hear the person on the other end clearly.”

“As I have reported I could hear those talking to me on the phone better than I had been able to in 25 years.”

REFERENCES

• 1 Dillion H, James A, Ginis J. Client-Oriented Scale of Improvement (COSI) and its relationship to several other measures of benefit and satisfaction provided by hearing aids.  J Am Acad Audiol. 1997;  8 27-43
• 2 Kochkin S. MarkeTrak VI: 10-year customer satisfaction trends in the US hearing instrument market.  Hear Rev. 2002;  9 14-25
• 3 Demorest M, Erdman S. Scale composition and item analysis of the Communication Profile for the Hearing Impaired.  J Speech Hear Res. 1986;  29 515-535