Interview with Shlomo Silman, Ph.D.
Topic: Dr. Silman's research, the EarPopper and new patent
CAROLYN SMAKA: This is Carolyn Smaka, and today I am conducting an interview with Shlomo Silman from an ark that's floating down the Hudson River.
SMAKA: Not really, but there sure is a lot of rain in the New York area today. Shlomo, thanks for your time.
SHLOMO SILMAN: I am happy to be here and out of the rain, Carolyn.
SMAKA: Shlomo, can we begin by discussing your background and your early research?
SILMAN: Certainly. I am Presidential Professor at Brooklyn College of the City University of New York (CUNY). Also, at the Graduate Center of CUNY, I am also a faculty member within the AuD Program and within the PhD Program in Speech-Language-Hearing Sciences.
In the late 1960s I worked with the United Nations in Tanzania, in what is today Zimbabwe, and in other places in Africa. I loved Africa and was inspired to help the people there. I wanted to go into medicine but then discovered audiology.
In the early years of my audiology career, I worked with a pediatric population at Queens Hospital and the Bernard Feinstein Developmental Center. Then, on an invitation from Dr. Stanley Gelfand, I joined the staff of the East Orange, NJ VA Medical Center as Chief Audiologist and worked there from 1976 - 1984. I had done research on the acoustic reflex and middle ear, and Stanley was an expert in reverberation and speech perception. We combined our expertise and collaborated on and published our research in these areas.
My research on the middle-ear muscles and otitis media resulted in the text, The Acoustic Reflex: Basic Principles and Clinical Applications (Ed. Silman, 1984). This text included chapters by the finest researchers from around the world, such as Harvard University, Karolinska Institute in Sweden, and the University of Trieste in Italy, and became the basis for many dissertations on the acoustic reflex and middle-ear studies.
Dr. Adrienne Rubinstein, then a doctoral candidate at CUNY working on a project at the VA, was instrumental in encouraging me to apply for a professorial position at Brooklyn College where she was Clinical Supervisor of Audiology. Subsequently, I was invited by Brooklyn College to join their faculty;I accepted the position and left the VA. At the time I left, I had been involved in the study of a very interesting phenomenon, adult-onset auditory deprivation. I found that in individuals with bilateral hearing loss who used only one hearing aid, the speech-recognition scores decreased significantly in the unaided ear over time while they remained stable in the aided ear. In those days, the protocol was to follow with ABR and site of lesion behavioral testing, so I did. I showed my data to Drs. Stanley Gelfand, John Lutolf, and Carol Silverman and they encouraged me to continue collecting data. I still remember the days when Dr. Lutolf brought cases to me now and again telling me "Here are more cases of deprivation supporting your theory."
I continued the investigation with the participation of Stanley and Carol and we submitted a manuscript to the Journal of Speech and Hearing Disorders. They rejected the article on the basis that the difference in speech recognition scores between the ears reflected just variability. Feeling strongly about our findings, we then submitted the manuscript to the Journal of the Acoustical Society of America which published it (Silman, Gelfand & Silverman, 1984). At Brooklyn College I, along with Drs. Silverman, Emmer, and Lutolf, further studied the phenomena of deprivation and acclimatization with federal funding.
SMAKA: What was the response to the article?
SILMAN: Well, there was no response. It was very interesting. No one supported it, there were no further publications or comments about the article and I became very frustrated because I believed the research had significant implications for clinical care.
So I decided to present the data on deprivation at various national and international conventions to start a professional dialogue and exchange on this topic. The first conference at which I presented was the International Congress of Audiology in Tenerife, Canary Islands, and following my presentation I was approached by Dr. Hans Verschure, from the Netherlands. He told me that a researcher by the name of Dr. Hans-Georg Dieroff in Germany had similar data corroborating my research, and gave me Dr. Dieroff's contact information.
With VA funding, I continued to collect data along with Drs. Silverman, Emmer, and Lutolf at Brooklyn College. Several audiology students were research assistants on our investigations. Some of these students pursued research as a career. One student, Keith Darrow, recently completed his Ph.D. in auditory physiology at MIT and Harvard. His research was published in Nature. Our further studies continued to support auditory deprivation as a phenomenon. The following year I presented the data at the International Congress of Audiology in Morioka, Japan. Dr. Hiroshi Hattori, from the Department of Otolaryngology, School of Medicine, Kobe University, told me that he had observed a very similar deprivation phenomenon in children. This was very encouraging. When I returned to the U.S., I learned that new articles on the topic of deprivation had been published by, among others, Raymond Hurley in the U.S. and Stuart Gatehouse from Scotland. I then spoke with Dr. James Jerger, who had always been supportive of this concept. He asked me to guest edit a special issue on the subject for the Journal of the American Academy of Audiology. This special issue appeared in 1993.
In 1995, the 1st Eriksholm Workshop on Auditory Deprivation and Acclimatization was held in Copenhagen. This conference represented a small group of leading researchers coming together to consider the impact of auditory deprivation and acclimatization for clinical practice and research design. The conference proceedings were published in Ear and Hearing (Arlinger et al., 1996). Now, finally, auditory deprivation was recognized on a global scale and these leading researchers came to a consensus on the presence of the phenomenon and presented guidelines for its identification and monitoring.
At Brooklyn College, I am supported by wonderful faculty members such as Drs. Gail Gurland, Adrienne Rubinstein, Rochelle Cherry, and in particular, Dr. Michele Emmer;I first met Dr. Emmer during her "audiological infancy" and then mentored her through her doctorate. Michele has joined me through years of productive research. In addition, I have access to a lot of great physicians such as Daniel S. Arick, MD., otolaryngologist.
SMAKA: Yes, I recognize Dr. Arick's name from some of your publications.
SILMAN: Yes, surrounded by all this expertise makes for the perfect environment to conduct research, such as research on middle-ear effusion in children. As in many audiology or ENT clinics, many children with recurrent otitis media came to the private practice of Dr. Arick, where I provided audiologic services for many years. I would see the patient charts and ask Dr. Arick, "Danny, what's going on here? Three months ago, you did surgery on this child and the child is coming back with the same problem. The tube is out. And what about this child? Here is another child who, over the past 9 months, had three ear surgeries that didn't help".
So the problem of recurrent middle-ear effusion became an area of interest for research. In addition, literature began coming out questioning the relation between language and middle-ear effusion in early childhood. I did not doubt the relation between middle-ear effusion and educational performance in school-age children. I feel that a prolonged conductive hearing loss, which often is the case with recurrent otitis media, has the same impact as sensorineural hearing loss on educational performance and emotional development. I did begin to question the relation between early otitis media and language acquisition. I'll tell you why I question the relation between early otitis media and language acquisition.
The most critical period for language acquisition and development is from birth to two years. At this age, children are generally very close to their mother or caregiver. When you are holding a baby in your arms, the distance between your mouth and the baby's ears is only 25 or 30 inches. When they're cuddled or carried, they are getting a much higher signal-to-noise ratio simply because of their very close distance to the mother's speech. In my opinion, the study by Paradise et al. (2005) conclusively showed the absence of a relation between early otitis media and language disorder.
SMAKA: Very interesting.
SILMAN: Indeed. One study I conducted used a sound level meter to measure the average level of the mother's speech at the baby's ear and it was about 70 - 80 dB SPL. I think this is likely the reason why many studies show no relation between otitis media and early language acquisition. For school age children, however, considerable research supports the conclusion that otitis media may adversely impact social and emotional development as well as academic performance.
SMAKA: Was this research the impetus behind the EarPopper, your patented device for treating middle ear air pressure issues?
SILMAN: Yes. Dr. Arick and I started looking into solutions and debating the issues. What type of treatment would be feasible for Eustachian tube dysfunction and middle-ear effusion, and what would be effective without the risks that accompany surgical insertion of pressure-equalization (PE) tubes? We knew the limitations of such surgery with our own patients. Valtonen et al. (2005) investigated the long-term outcomes of surgical insertion of PE tubes for treatment of recurrent otitis media with effusion in infants and young children. They found that roughly 50% of these children underwent multiple—3, 4, and more—ear surgeries. The outcomes of PE tubes were examined in children who had been referred for surgery on the basis of the otoscopic exam without consideration of the hearing status. If the presence of hearing loss had been included as a criterion, it is likely that the percent receiving multiple surgeries would be much higher. One would anticipate spontaneous recovery in the children with middle-ear effusion who also had normal-hearing sensitivity, so that only the more severe cases would be referred for surgery and these more severe cases would probably require more than one surgery.
I have had patients who have had surgical insertion of PE tubes as many as eight times, with persistence of the problems, along with issues such as perforation, scarring, etc. Mothers literally come in crying from frustration. Why is this surgery often not effective? The answer is simply because it does not address the underlying cause or etiology of otitis media with effusion.
So in light of all of this, we decided to look for alternative solutions. And during our investigations we looked at a device called a Politzer bag that was used in the past by physicians but is no longer in use today. The small bag is connected to a tube that is inserted into the nose, and the physician would ask the patient to swallow. While the patient swallowed, the physician squeezed the bag. The idea was that this general pressure would open the Eustachian tube and aerate the middle ear.
One problem with the Politzer bag, however, is that physicians didn't know how much air pressure to put into the ear, and there was no control over the air pressure with this device. One can obviously cause damage to the ear with too much air pressure. Another problem with the bag was that coordination between inserting the air pressure and swallowing is very hard to achieve with children.
So, the idea of the Politzer bag was good in principle, and we decided to develop an engineering solution to overcome its limitations. Here is where hearing science, audiology, and medicine all got involved in a fascinating collaboration.
We developed a small, battery-operated device, now called the EarPopper, which emits a controlled volume of air according to the user's age, hearing loss and amount of fluid in the ear. The control of air volume flow and pressure according to these parameters ensures that the device is extremely safe. The total duration of the air flow is less than one second. We conducted a pilot study in the ENT private practice where I provided audiologic services and the results were great. Consequently, Dr. Arick and I spoke with Dr. Jerry Northern, who happened to be in New York City at the time, who suggested that we form a small business so we could apply for a grant from the Small Business Innovation Research (SBIR) Program of the National Institutes of Health (NIH).
We formed a company and applied for the NIH SBIR grant. There were two stages: feasibility studies and clinical trials. For the feasibility studies we received NIH funding of about $50,000 -60,000, and we had beautifully engineered devices and we were successful. We then received about $1 million for the clinical trial at Brooklyn College. An advantage of doing the trial at Brooklyn College was that students could directly learn about the research aspect of our profession and how audiologists and otolaryngologists can work together for the same goal.
Based on the innovation of the EarPopper and its success in treating otitis media with effusion and Eustachian-tube dysfunction through non-surgical and non-pharmacologic means, Dr. Arick and I each were given the prestigious National Tibbetts Award in the area of Medicine. This award was sponsored by several agencies including the National Aeronautics and Space Administration (NASA), the Department of Defense (DoD), NIH, and the National Science Foundation (NSF).
SMAKA: What was the outcome of the clinical trial?
SILMAN: The clinical trial took us about three years and the results were great. Middle-ear effusion was resolved in 74% of those who used our EarPopper and in only 26% of the control group. We published two articles in medical journals, one regarding the clinical trial (Arick & Silman, 2005), and the other one was the follow-up (Silman, Arick, & Emmer, 2005). When I say follow-up, this refers to those 26% in whom middle-ear effusion was not resolved by the initial use of the EarPopper. In the follow-up study, we extended the treatment period with our device for another 3-4 weeks, and the results led to an increase from 74% to 84% in the overall success with the EarPopper.
As a result of the success of our clinical trial, we received a lot of publicity on major networks, newspapers and so forth, and we were contacted by a well-known medical device company called Micromedics. They had done their own feasibility study. Ultimately we accepted their offer to lease the device, which led to the device's commercialization.
The recent findings of Goto et al. (2007), published in the Journal of Oto-Rhino-Laryngology of Tokyo further substantiated our findings with the EarPopper. Their data showed even greater success rates (86% - 89%) than what we had obtained.
Dr. Yehudah Roth, who is at Edith Wolfson Medical Center of the Tel Aviv University Sackler Faculty of Medicine, had positive results in two separate trials with the EarPopper. He and his colleagues currently are in the writing stage to prepare a manuscript submission for publication. One study was a clinical trial to investigate the efficacy of the EarPopper for treatment of middle-ear effusion in children. The other study used the EarPopper prophylactically to see if it prevented middle-ear effusion in healthy kindergarten children. Based on personal communication with Dr. Roth, the results of his studies are reportedly encouraging. The major medical centers in Israel are using the EarPopper as treatment, and are reserving/surgical insertion of PE tubes as a last resort. We are looking forward to seeing the published results of those studies.
Now we are in the process of applying for a grant to NIH to study the feasibility and efficacy of the EarPopper with younger children between 2 and 4 years of age, as previous studies had been on children who were 4 or more years of age. We have made some modifications in the device for children in this age range.
In addition, Dr. Emmer and I have developed a device based on the Politzer principles, for use in infants and very young children. You can't tell infants, "You're going to feel some pressure in your nose, and you should swallow when I tell you to swallow". We just received a U.S. patent for the methodology of this modified device for infants and young children between 6 months and 2 years of age. We are now developing a prototype of the device. This is incredibly exciting for us.
SMAKA: Congratulations on the patent. When do you think a device for babies would be available on the market?
SILMAN: It's hard to say. Now that we have the patent we are working with engineers on developing a prototype. This device involves a pacifier that the baby sucks, and whenever the baby sucks with the pacifier and swallows, air goes through the tube in his nose and then opens the Eustachian tube. The device contains a flap and balloon. Whenever the baby swallows, the balloon inflates, the flap closes, and the direct pressure opens the Eustachian tube.
We are trying out this device on adults including ourselves. We can feel the ear pop, which is evidence that is accomplishing the goal. We are going to have to do intensive studies and submit it to the Food and Drug Administration (FDA). The EarPopper received FDA 510(k) approval for marketing as a prescriptive medical device.
SMAKA: Fascinating. To switch gears for a moment, how is the Au.D. program going?
SILMAN: As you know, Brooklyn College is part of an the CUNY Au.D. consortium that also includes the Graduate Center and Hunter College of CUNY. Courses and clinical practica take place at each of these campuses. It's going very well. We have a renowned faculty, and a very high caliber of students. Believe it or not, we have students with degrees in engineering, psychology and other diverse majors in the Au.D. Program. It's exciting to be part of such a dynamic program, which also has an emphasis on research. Dr. Barbara Weinstein is the energetic leader of this program. The Co-Directors Dr. Carol Silverman (Hunter College) and Dr. Adrienne Rubinstein (Brooklyn College) also contribute to the leadership.
SMAKA: Shlomo, thanks for all your time today for sharing with us about your research, the EarPopper, and this new patent you received to address middle ear effusion in infants.
For audiologists who are not familiar with the EarPopper, where can they get more information or where they can purchase one?
SILMAN: It's been a pleasure. For audiologists unfamiliar with the EarPopper, please go to www.EarPopper.com. To view the electromechanical system of the EarPopper, refer to Silman, S & Arick, D. (1999).
Arick, D.S. & Silman, S. (2005). Non-surgical home treatment of middle-ear effusion and associated hearing loss in children. Part I: Clinical trials. Ear, Nose & Throat Journal, 84(9), 567-578.
Arlinger, S., Gatehouse, S., Bentler, R.A., Byrne, D., Cox, R.M., Dirks, D.D., Humes, L., Neuman, A., Ponton, C., Robinson, K., Silman, S., Summerfield, A.Q., Turner, C.W., Tyler, R.S., Willot, J.F. (1996). Report of the Eriksholm Workshop on Auditory Deprivation and Acclimatization. Ear and Hearing,17(3 Suppl),87S- 98S.
Goto, F., Yabe, H., Goto, K., Ogawa, K. (2007). Ear popper: New device to treat otitis media with effusion. Oto-Rhino-Laryngology, Tokyo, 50(5), 330-332.
Paradise, J.L., Campbell,T.F., Dollaghan,C.A., Feldman, H.M., Beverly S. Bernard, B.S., Colborn, D.K., et al. (2005). Developmental outcomes after early or delayed insertion of tympanostomy tubes. New England Journal of Medicine, 353(6), 576-586.
Silman, S. (Ed.) (1984). The Acoustic Reflex: Basic Principles and Clinical Applications. New York: Academic Press.
Silman, S & Arick, D. (1999). Efficacy of a modified politzer apparatus in management of Eustachian tube dysfunction in adults. Journal of the American Academy of Audiology, 10(9), 496-501.
Silman, S., Arick, D.S., & Emmer, M.B. (2005). Non-surgical home treatment of middle-ear effusion and associated hearing loss in children. Part II: Clinical trials - validation. Ear, Nose & Throat Journal, 84(10), 646 - 650.
Silman, S., Gelfand, S.A., Silverman, C.A. (1984). Late-onset auditory deprivation: Effects of monaural versus binaural hearing aids. Journal of the Acoustical Society of America, 76, 1357-1362.
Valtonen H, Tuomilehto H, Qvarnberg Y, Nuutinen J. (2005). A 14-year prospective follow-up study of children treated early in life with tympanostomy tubes: Part I: Clinical outcomes. Archives of Otolaryngology—Head & Neck Surgery, 131(4), 293-298.