experiences to date comfort levels must be checked before the procedure is started 11 adults have...
TRANSCRIPT
Experiences to Date
Comfort levels must be checked before the procedure is started11 adults have been fitted and did not like the initial DSL fitting targets and were then fitted using NAL. 4/11 have preferred a base cut at the first fitting already moving away form the NAL-RP targetsThe full balancing procedure with frequency shaping is time consuming even with adults
IntroductionThis paper describes a multi-centre UK initiative to investigate the benefits of fitting a contra lateral hearing aid with a cochlear implant in experienced paediatric users. Current published research shows the benefits of fitting a hearing aid in the contralateral ear using a special balancing procedure.1
However this procedure is based on the NAL-RP fitting prescription. In the UK the most commonly used fitting prescription used for children is Desired Sensation Level (DSL i/o)2. The balancing procedure outlined in the published literature has been modified to produce a generic protocol (see handout). This modified procedure has been further reduced to make it clinically practical to perform with younger children.
AimsCan the the benefits of using a contralateral hearing aid be replicated using the loudness-balancing element only of the published procedure and the DSL i/o fitting prescription?
Optimising the Fitting ofHearing Aids with Cochlear Implants
Sarie Cross1, Paula Greenham2, Sarah Flynn1, Catherine Broxholme3, Maire Doran4
1.ISVR, University of Southampton. 2.Cochlear Europe Ltd. 3. Great Ormond Street Hospital, London. 4. Glan Clwyd Hospital, North Wales.
References
1 Should Children Who use Cochlear Implants Wear hearing Aids in the Opposite Ear? Ching T, Psarros P, Hill M, Dillon H. & Incerti P. Ear and Hearing
2001: 22, 365-3802 The Desired Sensation Level Method for Hearing Aid Fitting in
Infants and Children Seewald, R. Phonak Focus No 20
Modified Paediatric Procedure
1 Fit the HA according to DSL targets for gain and maximum output. Do not be concerned if the gain targets above 1 kHz are not achievable. The implant system will contribute the high frequency information.
Confirm fitting with real ear measurement.
2 Adjust the overall gain and/or compression characteristics of the HA so that the loudness of speech in the ear with the HA is matched to that in the implanted ear at soft (55dB SPL), average (65dB SPL) and loud speech levels (80dB SPL).
This is achieved with the Supero by;a) Adjusting G50 with an input level of 55dB SPLb) Adjusting G80 with an input level of 80dB SPLc) Check balance at 65dB SPL by adjusting overall gain if
required
3 Confirm new fitting with real ear measurement.
4 Finally check that the loudness of both implant and HA together is comfortable with 80dB SPL input.
Fit and Optimise
Hearing Aid
Administer
Baseline Questionnaire
Localisation Testing
11 speakers
Anechoic chamber
ISVR, Southampton
Evaluate
Speech Performance
CI Alone and CI with HA
Administer
Follow up Questionnaire
Study Protocol
Subjects: 6 years of age or overExperience: Stable MAP for 6 months and have
not used hearing aid for 1 yearPersonnel: Experienced HA AudiologistEar Moulds: Comfortable rather than tight/deep
fit Equipment: HA Programming and
Real Ear Measurement Equipment Hearing Aid: Phonak Supero 412Fitting Protocol: Desired Sensation LevelBalancing: Adjust the output of the HA to
match the overall loudness of the CIListening Trial: 8 weeksSpeech Testing: IHR Sentences – adaptive
procedureFunctional Benefit: PEACH questionnaire Localisation Testing: 11 speakers in anechoic chamber Parallel Study: Study with Adult subjects to
validate generic balancing fitting procedure with standard prescribed fitting
Further information from:
Sarie Cross, SOECIC, ISVR, University of Southampton
Identify Patients
Obtain Consent
Earmould Impressions
The Authors would like to acknowledge Phonak U.K. for their support with this study.
Geneva 2004