Interview with Ravi Sockalingam, Ph.D. Director of Clinical Research, Oticon Medical

Topic: Clinical Research at Oticon Medical

Ravi Sockalingam, Ph.D.

CAROLYN SMAKA: Today I'm speaking with Dr. Ravi Sockalingam from Oticon Medical. Ravi, welcome to AudiologyOnline.

RAVI SOCKANLINGAM: Thank you.

SMAKA: Ravi, what is your role at Oticon Medical?

SOCKANLINGAM: I am Director of Clinical Research and Professional Relations. I plan, coordinate, and facilitate clinical research projects carried out in North America and Europe for Oticon Medical. This includes a wide range of clinical projects as well as development projects in bone conduction technology.

We are constantly looking at innovative ways of treating hearing loss that can't possibly be overcome with air conduction hearing instruments. Bone conduction technologies are being used for a many years now, but the technology used in the sound processors lags far behind the technology used in conventional air conduction hearing instruments. However, in the last eighteen months we have witnessed a quantum leap in the design and signal processing technology used in bone conduction sound processors. These advancements are based on a solid foundation of knowing what works best for our patients through many years of research. When I speak of research, I'm referring to a broad spectrum of projects, from developmental projects in basic sciences to product-oriented projects that investigate how products perform in the marketplace.

There is a lot of interest and enthusiasm from the clinical community -audiologists and otolaryngologists (ENTs) alike - to undertake studies to evaluate the performance of our bone anchored systems on their patients. These studies involve the audiology processor as well as the actual implant fixture.

In addition to being responsible for clinical research projects for the company, I'm also involved in building relationships with centers delivering bone conduction hearing solutions in terms of supporting them in their educational and training activities. It's only by working closely with them and listening to their needs that we can achieve the best possible outcomes for the patients we serve.



SMAKA: What did you do prior to your new position at Oticon Medical?

SOCKANLINGAM: Prior to joining Oticon Medical, I worked as a Senior Audiologist and Manager of Audiology Communications at Oticon's corporate headquarters in Denmark. I was there for three years as part of the audiology group developing and communicating the audiology concepts in Oticon technology.

When we develop a new innovative concept, and when we know it's going to improve or meet specific patient needs, we disseminate the information by publishing in trade journals or presenting at professional conferences. Among the many projects I was involved in was a study we did with clinicians and patients to find out firsthand how well a specific hearing instrument did in the real world in terms of performance, handling, etc. This is no different from what I am currently doing in Oticon Medical.

I got my training in speech-language pathology and audiology from the University of Queensland in Brisbane, Australia. I'm originally from Singapore, so I went back home to practice after graduating from college - I worked a Speech-Language Pathologist for three years before making the switch to audiology. That's when I had the opportunity to set up advanced diagnostic services and a totally in-house hearing rehabilitation service in a major hospital in Singapore.

SMAKA: Very interesting!

SOCKANLINGAM: Yes, that was in 1994. It is the second largest hospital in Singapore and some of their advanced diagnostic services were not yet in place at the time.

SMAKA: What kind of research did you do for your Ph.D.?

SOCKANLINGAM: I started my Ph.D. in '96 as I had the urge to go back to university and to embark in research. I went back to Queensland University and in my second year of studies, I received a one-year doctoral fellowship from the Lady Davis Fellowship Trust to pursue research at the prestigious Hebrew University of Jerusalem-Hadassah Medical School in Israel. I had the rare opportunity of working in the auditory physiology laboratory of Professor Haim Sohmer, and it was a indeed a privilege to work in his laboratory.

I did my research on cisplatin-induced ototoxicity. I started off working on the human population in Brisbane, Australia, but I wasn't getting enough subjects, so I switched to animals. I looked at dogs in Brisbane, and small laboratory animals in Israel including a special breed of rodents called fat sand rats that are native to sub-Saharan Africa. that are a very good model for hearing research. We studied the mechanisms of cisplatin ototoxicity by investigating the pharmacokinetics of cisplatin and auditory measurements, namely, OAE and ABR. Interestingly, dogs, like humans, are treated with cisplatin for a variety of carcinomas by veterinary oncologists.

After I completed my Ph.D., I taught at the University of Queensland, and later at Dalhousie University in Halifax, Canada. After four years in Halifax, I decided to move back to the southern hemisphere for a position at the University of Canterbury in New Zealand.It was very exciting to be part of their new program in audiology. From there I was offered an opportunity with Oticon.

SMAKA: Was it difficult to transition from academia to industry?

SOCKANLINGAM: Not really. I always wanted to work in a manufacturing environment and see what actually goes on in R&D, so it was an exciting time. It was a wonderful experience for me because I learned a lot about hearing instruments and the development process, how they actually begin as a concept and are eventually brought to the market place. I also learned a tremendous amount about how the technology actually works;it was a great learning experience.

Oticon is a totally people-focused company. Part of the company culture is sharing everything we know and learn. That was invaluable;there was always someone to enlighten me when I wanted a deeper understanding of something. And I was able to share my clinical knowledge for people like engineers who may have wanted information from an audiologist's perspective.

SMAKA: What an interesting background you have. Regarding bone conduction implants, what are some of the latest advancements and what developments are on the horizon?

SOCKANLINGAM: Initially, with bone conduction implants, there was only a single manufacturer and the technology didn't really keep up with advancements in hearing instrument technology. Just in the last eighteen months, we have seen significant developments in design and performance of bone-anchored processors. When Oticon Medical entered the bone-anchored hearing system market, we brought with Oticon's proven track record in advanced hearing aid technology.

We now have several technologies never seen before in bone anchored solutions. Users of bone conduction hearing systems can now take advantage of new innovative technologies designed to improve speech fidelity and speech understanding in noisy situations. We have automatic adaptive directionality with two kinds of directional systems - full directionality and high frequency directionality- that can potentially offer more opportunities to the patient to experience improved speech understanding in noise. We also have intelligent noise management systems designed to improve listening comfort in noise and to reduce annoyance from wind noise. These technologies are relatively recent developments and we can expect to see further developments in this area. Better designs to improve reliability and to facilitate better handling and use of the bone anchored systems are also being witnessed.

As far as fitting of hearing instruments goes, we are moving toward in-situ audiometry and in situ real ear gain. We can individualize gain targets easily and more accurately by measuring the thresholds and determining gain targets from the individual ear. Now, we have the same development in bone conduction solutions where we are able to actually measure bone conduction thresholds directly from the processor, instead of using the regular bone conduction vibrator. We know that with the placement of the B71 vibrator on the skull to measure bone conduction thresholds, there is a lot of variability. We can minimize this variability by measuring individual bone conduction thresholds straight off the abutment site.

We also know that sound energy is lost through transcranial attenuation as the sound travels through the skull. When you fit a bone conduction implant for single-sided hearing loss there will always be a loss of sound due to transcranial attenuation. Once we know the transcranial attenuation and can accurately determine the bone conduction threshold through the processor, we can more accurately determine gain targets.

Until now, we were measuring thresholds in the sound booth, fitting the processor and patients were happy because they could hear sound that they couldn't hear before the fitting. But did we give the right amount of gain? That is the question we ought to ask ourselves.

We also have people now working on prescription formulae specifically for bone anchored devices, which will hopefully lead to verification of the fittings. All these means improved outcomes for the patients.

SMAKA: You've talked about developments with the speech processor and fitting process, what about the surgery? Are there improvements to be made there?

SOCKANLINGAM: Today there is no real consensus on what surgical technique would achieve the best outcomes for the patients. For instance, there are differences in opinion with regards to the type of incisions made and the amount of soft tissue that is taken out across clinics and between surgeons. Also, the diameter of the implant that has the potential to impact implant stability and the timing of loading the processor post surgically is one issue that warrants systematic investigation. We may in the near future see the emergence of new surgical techniques that might take care of some of the issues we face today with connective tissue. Alternative bone conduction solutions that don't require skin grafts at all might also be in the horizon.

From an audiological standpoint, I would expect that we will see developments in the decision process that would ultimately result in the patient being fitted with a sound processor that best serves their needs.

SMAKA: Earlier you mentioned Oticon Medical entering the bone conduction solution arena. It seems to be a burgeoning area.

SOCKANLINGAM: Yes. We believe that clients should have options. Imagine if there were only one company making hearing instruments and you had to go with that company even if that company was delivering a good product? People are more comfortable knowing there is more than one company out there investing and researching in bone conduction solutions. As a professional, you can try all available solutions and then decide which to recommend for your patients.

SMAKA: If a clinical site wanted to get involved with bone conduction implants, how would they start gathering information to determine if it's a fit for their practice?

SOCKANLINGAM: They could call Oticon Medical at 1-888-277-8015 or send an e-mail to Info@.oticonmedical.com. If a practice is currently fitting implants and would like to get involved in research, I would encourage them to contact me directly at rxs@otiuconmedicalusa.com

SMAKA: Ravi, great to talk to you and thanks for your time today.

SOCKANLINGAM: Thanks for the opportunity. Have a great day.

For more information about Oticon Medical, please visit www.oticonmedical.com or the Oticon Medical Web Channel on AudiologyOnline.