Newsletter February 2004

AbstractRehabilitation for high frequency sensori-neural hearing impairment in adults

with the Symphonix Vibrant Soundbridge.

Objective: To assess and compare the subjective and objective performance benefi ts obtained with conventional amplifi cation and an implantable middle ear implant, the Symphonix Vibrant Sound-bridge (VSB) using the SIGNIA speech signal technology for adults with high frequency hearing loss.

Study design: A single subject repeated measures study design was used for a comparative evaluation of conventional amplifi cation and a middle ear implant, the VSB. Objective audiometric measures were performed in 3 conditions for the implant ear postoperatively: unaided; aided VSB using the SIGNIA processing circuitry and aided SIGNIA hearing aid following a brief postoperative trial. Subjective measures both standardized and non-standardized were used to evaluate the patients reports of the benefi ts obtained from conven-tional hearing aids worn preoperatively versus those obtained from implanted amplifi cation postoperatively.

Setting: 1 tertiary teaching hospital and 1 hearing aid specialist fi t-ting offi ceSubjects: 6 patients displaying a high frequency hearing loss im-planted with the VSB with an average of 17 months post-surgery experience. The degree of loss across the frequency range was mild to profound, dominated by a hearing defi cit for the high frequencies in each case.Intervention: Rehabilitative

Results: Speech comprehension mean scores for the group in quiet and in noise are statistically signifi cantly improved with the VSB in comparison to those obtained when using conventional amplifi cati-on using the same SIGNIA processing technology. In comparison to the preoperative conventional hearing aid, satisfaction reported on the HDSS for a variety of user issues related to quality of life, ease of use, comfort, cosmetics, occlusion effect and feedback was signifi -cantly improved with the VSB. Via the APHAB, listening was repor-ted as signifi cantly easier in a variety of situations with background noise and reverberation for the group with the VSB in comparison to the preoperatively worn hearing aid.

Conclusion: The Vibrant Soundbridge using the SIGNIA processing technology, offers improvements to speech comprehension in a variety of listening situations and to overall satisfaction in compa-rison to conventional hearing aids for patients with sensori-neural hearing impairment predominantly for the high frequencies. Despite the small number of individuals investigated for this study, the sta-tistical signifi cance of the data establishes the VSB as an effective rehabilitative alternative for the treatment of high frequency hearing impairment.

Key Words: middle ear implant; high frequency sensori-neural hea-ring loss; rehabilitation; Symphonix Vibrant Soundbridge.

Hearing Technology GmbH,Fürstenweg 77,

A-6020 Innsbruck,Austria

www.vibrant-medel.com

Funding source: No costs directed to the clinics or patients.

Corresponding author: Professor Alain Uziel

Hôpital Guy de Chauliac - Service ORL2 Av Bertin Sans

34295 Montpellier CedexTel: +33 (0)4 67 33 6890 - Fax: +33 (0)4 67 33 6829

Email: a-uziel@chu-montpellier.fr

Running head: VSB for High frequency hearing loss

Authors: Alain Uziel, MD. Ph D.

Hôpital Guy de Chauliac, Montpellier, France Michel Mondain, MD. Ph D.

Hôpital Guy de Chauliac, Montpellier, France P Hagen, MD.

Hôpital Guy de Chauliac, Montpellier, FranceFrançois Dejean

Laboratoire d ’Audition des Arceaux, Montpellier, FranceGuilhem Doucet

Laboratoire d ’Audition des Arceaux, Montpellier, France

Graphics for the HF Montpellier paper N=6.Fig 1. Individual hearing thresholds for the implant

ear preoperatively, N=6.

Vibrant® Soundbridge®User Climbs Mountain in the Himalayas

Soundbridge user Michel M. in the Himalayas at 5500m In the background Mt. Everest (8848m) and Lotse (8516m)

Michel M., a Vibrant Soundbridge user from France, recently clim-

bed one of the peaks in the Himalayas near Mt. Everest. He climbed

up to a peak of 5500 meters (ca. 18,000 ft.) and was able to wear his

Vibrant Soundbridge Audio Processor without any problems.

Michel received his Vibrant Soundbridge in Marseille in Decem-

ber 2001. Before implantation he wore digital ITE hearing aids but

complained about loud sounds, feedback and insuffi cient overall

benefi t. With his Vibrant Soundbridge, Michel now reports benefi ts

including greatly improved sound quality in noisy situations and

wearing comfort. Michel still uses an ITE hearing aid in the other ear,

but he is a candidate for bilateral implantation and plans to receive

his second Vibrant Soundbridge in 2004.

Mr Bizaguet is in charge of about 15 VSB pati-ents. He works as hearing aid dispenser in Paris and is well recognized in the fi eld for his com-petency and knowledge of implantable hearing devices. Moreover, his relationships with doc-tors and among hearing aid dispensers make him an essential partner in the development of this type of middle ear implants.

Questions to Mr Bizaguet :

o What are the audiological tests to implement before the surgery of a middle ear implant such as the VSB ?

The usual audiological tests must be implemented. A search of distortions in the inner ear seems to be a predictor since, as it is the case with other hearing devices, the limiting element of the VSB is the quality of the cochlea. In case of important damage in the cochlea, the result may be unsuccessful related

to the psychological involvement of the surgery. In case of high frequency hearing loss, searching for dead cochlear regions is essential.

o According to you, what are the ideal indications for a Vibrant Soundbridge middle ear implant, and why ?

The best indications are the high frequency hearing losses with an important slope in the highs, with good lows and suffi cient cochlear cells in the highs. The impossibility for the patient to accept his own voice due to the ear canal occlusion is another eventual indication as a fi rst choice for amplifi cation.

o What is the importance of the relationship with the ENT doctor as far as caring of VSB implanted patients ?

The audiologist can play three roles : fi rst, as a professional to check that the problems encountered with the previous hearing device are not due to malfunction or inadequate settings. Second, as a partner to assist the patient in the preparation of

implantation and then in the adjustment of the audio processor. Lastly, in the usual follow up of the fi tting of a hearing impaired patient.

o Is today the middle ear implant considered as a fi tting solution that can be offered to hearing impaired patients ?

The middle ear implant is not a fi rst choice solution yet, but an alternative for some patients in the case of diffi culties encoun-tered with conventional hearing aids. The mental involvement must correspond to the uncomfort experienced by the hearing impaired patient.

Mr Doucet has fi tted 25 patients with a VSB; all of them present a high frequency hearing loss but 18 out of 25 have a hearing loss with a dras-tic slope in the high frequencies referred as “ski slope”.

Questions to Mr Doucet :

o In your daily activity, what is the percentage of patients pre senting a “ski slope” hearing loss ?

This type of hearing loss only represents 5 to 10%. However, the real number is bigger but the prescribing doctors are a little re-luctant to hearing aid devices in this case due to the bad results obtained with an ITC or BTE hearing aid.

o Were the 25 implanted patients that you follow up fi tted with conventional hearing aids before implantation and with what kind of devices ?

All the patients coming from public hospitals were implanted after unsatisfying results with ITC or BTE hearing aids. Some patients coming from private practices were implanted with the VSB as the fi rst choice solution.

o Why is the VSB appropriate for these “ski slopes” hearing losses ?

The absence of any occlusion of the ear canal and the high func-tional gain provided beyond 2 KHz without any feedback make the VSB particularly well adapted for the “ski slopes”.

o What is your patients satisfaction level ?

The satisfaction level is due, on one hand, to the physical com-fort of an absence of foreign body in the ear and also to the light weight of the audio processor; on the other hand, it is due to the natural sound of the patient’s own voice and the high tolerance to amplifi cation of high frequency sounds which are less accep-ted with an ITC or BTE hearing aid.

o Is the VSB fi tting very different from the one of a BTE or ITC hearing aid containing the same Signia chip ?

The connection to the processor and the access to the fi tting is the same as for the BTE. However, it is better not to rely too much on the pre-fi t curve and to not overuse the noise reduction algorithm and the compression in order to give the largest dyna-mic range possible. The impossibility to obtain a response curve through an electroacoustic box is compensated by a functional gain, done in sound fi eld with warble tones, in order to know the actual gain provided.

o What are the results (functional gain, speech intelligibility) you obtain with the VSB in “ski slopes” hearing losses ?

Our published study on the results between VSB and a Signia BTE has shown that for speech intelligibility in quiet the difference is not very important but it is very signifi cant for speech intelligibility in noise, even when the BTE directional microphone is activated. The patients satisfaction is much in favor of the VSB for its hearing comfort and “non-prothetic” aspect.

o According to you, what are the limits of the VSB?

The VSB is of no utility in dead cochlear regions, and it is essential to keep it for high frequency hearing losses with good lows.

o What are your results with the DDS (Direct Drive Simulator) used pre-surgery ?

For the patients, being able to experience the VSB sound quality before the implantation is essential in order to reassure them. Moreover, we can also achieve some sound fi eld tests such as functional gain and speech which allows us to compare the con-ditions unaided, aided with conventional hearing aid(s), and the DDS. The hearing aid dispenser is then able to realize what the improvement could be with the implanted VSB.

o Is the VSB middle ear implant one the fi tting solutions you offer to hearing impaired patients?

Of course. The VSB is offered as a solution to hearing impaired patients unsatisfi ed with their hearing aids, with good low fre-quency hearing, and having an active life.

INTERVIEW with Mr Eric BIZAGUETAudioprothésiste DE

(Laboratoire de Correction Auditive, rue Thérèse, Paris)

INTERVIEW with Mr Guilhem DOUCETAudioprothésiste DE

(Laboratoire d’Audition des Arceaux, Montpellier)