Telephone use and understanding in patients with cochlear implants

Ear, Nose & Throat Journal, Feb, 2004 by Jeffrey S. Adams, M. Suzanne Hasenstab, Gregory W. Pippin, Aristides Sismanis

Abstract

We conducted a mail survey of patients who had received cochlear implants to ascertain their ability to communicate on the telephone. Of 86 patients who responded, 38 (44 %) did not use the telephone at all, 36 (42 %) were able to use the telephone without assistance (independent users), and 12 (14%) were able to use the telephone with some type of assistance. Factors associated with independent use were male sex, older age at the onset of hearing loss, longer duration of hearing loss, successful use of hearing aids prior to cochlear implantation, implantation with a MED-EL Combi 40 device, and a shorter duration of implant use. But regardless of circumstances, our findings suggest that many cochlear implant patients can use the telephone during daily activity without the need for assistive devices or relay services.

Introduction

Severe to profound hearing loss can limit or even preclude telephone communication, even among patients who use a hearing aid. Although studies have shown that cochlear implants have a positive effect on speech perception and speech production in such patients, (1) telephone competency is more difficult to achieve. Communication by telephone requires understanding speech without visual cues in an environment of transmission inhibitors such as distortion and noise. (2)

Studies addressing the effect of cochlear implants on telephone performance are sparse. There were, however, some investigations in the 1980s and 1990s that documented successful telephone use following implantation) s Most of these studies focused on the telephone performance of patients who used the Nucleus 22 implant (Cochlear Corp.; Lane Cove, New South Wales, Australia):

* Brown et al reported the case of an adult multichannel cochlear implant user who was able to correctly repeat 21% of the key words on the Central Institute for the Deaf (CID) Everyday Sentences Test spoken over the telephone on the first attempt. (3) When the sentences were repeated, the patient's accuracy increased to 47%.

* In a study of 28 elderly patients, Kelsall et al reported successful telephone use without the assistance of a telephone code by 6 patients (21%). (4)

* Facer et al studied telephone use in 43 postlinguistically deaf adults who had a Nucleus 22 implant and found that telephone use was possible in 33 (77%). (5) Three other patients were able to use the telephone with the assistance of a code, and I was able to use the telephone to a limited degree.

* Cohen et al selected 8 of their adult Nucleus 22 recipients who demonstrated any degree of open-set speech discrimination for evaluation. (2) Five demonstrated competency in telephone communication.

* In a study by Ito et al, 10 of 10 adult Nucleus 22 cochlear implant recipients who performed in the SPEAK coding strategy were able to easily understand natural voice conversations. (6) However, when these patients were evaluated for telephone listening ability, their performance was not satisfactory without the assistance of a telephone adapter.

* Cochlear Corp. studied long-distance telephone speech recognition in 67 postlinguistically deaf adults who used the Nucleus 24 cochlear implant. (7) Improvement over preoperative performance with hearing aids was noted in 61 patients (91%) on the CID Everyday Sentences Test and in 53 (79%) on the Psychoacoustic Laboratory Sentences Test. Median scores were 66 and 65%, respectively. Some 21% of patients recognized more than 90% of the key words during telephone tasks.

* In a study of 47 adults with a Clarion Multi-Strategy Cochlear Implant (Advanced Bionics Corp.; Sylmar, Calif.), Lalwani et al noted that two-thirds understood at least 50% of the material on the Overlearned Sentences Test transmitted via telephone. (8) Half of these patients understood at least 75% of the material.

* In a more recent study at the authors' institution, 8 postlinguistically deaf adults implanted with the MEDEL Combi 40 device (MED-EL; Innsbruck, Austria) programmed in the CIS mode achieved a mean score of 87% on the CID Telephone Sentences Test transmitted via a standard telephone after 12 months of implant use; 5 of these patients achieved scores of 96% or higher, including 2 who achieved 100% accuracy. (9)

In this article, we describe the results of our study of telephone use among cochlear implant recipients. Our goals were (1) to identify patients at our institution who were able to use the telephone independently and examine their clinical, audiologic, and cochlear implant device characteristics and (2) to identify characteristics associated with the best performances on the CID Telephone Sentences Test.

Patients and methods

Patient selection. We accessed the patient database at the Department of Otolaryngology-Head and Neck Surgery at our institution to identify all patients who had undergone cochlear implantation between Jan. 1, 1987, and Feb. 28, 2001. All surgeries had been performed by 1 of 2 implanting surgeons during that time. All patients had been born prior to Dec. 31, 1991. Prior to testing, all patients had used their cochlear implant for at least 6 months.