This month, our new “Products in Practice: Focus On” feature taps readers into what distributors and practitioners are saying about OAE screeners. The otoacoustic emission (OAE) screen measures an echo from the inner ear in response to a sound from a probe positioned in the ear canal. Our roundup represents the views of participants and is not intended to be a scientific survey.

Distributors were asked:

  • What are your best-selling products?
  • Why are those items selling versus alternative products?
  • Tell us about changes you envision down the road.

Jane Dalaa,
product manager,
GN Otometrics, Denmark headquarters
GN Otometrics North America, Schaumburg, Ill

The MADSEN AccuScreen is very popular worldwide. It features all standard screening technologies. Several national and regional hearing-screening programs have been implemented using this handheld screener. It offers three types of screening technologies: TEOAE and DPOAE, in addition to the “gold standard” ABR. Due to the DPOAE and AABR features, it can be used to screen patients of all ages. It lets you store results from up to 250 individual patient tests in its own built-in memory, and with the AccuLink, it interfaces to printers and PCs for full patient documentation. The design is simple and has a menu-based interface. We are constantly monitoring the market for screeners, and we continuously release updated versions of the AccuScreen and AccuLink software. We try to make sure that all of our customers always are informed of updates by our sales companies and through our well-established distributor network.

David P. Speidel, MS, FAAA

David P. Speidel, MS, FAAA,
director of audiology services,
Interacoustics, Eden Prairie, Minn

The most successful OAE device within the Interacoustics product line is the OtoRead. The popularity of this model is due to the various configurations available to meet the needs of most clinics, along with its small footprint, sleek design, DP and TE stimulus choices, and portability. Test results are quickly printed via a small strip chart printer, but an optional database program accepts data from the OtoRead and presents it in an attractive 8 by 11 color format for more professional reports. Reasons for the popularity of the OtoRead over our other PC-based products are that clinicians seem to be looking for OAE devices that are versatile and have a lower cost. It offers testing capabilities that rival more complex PC-based products, plus it is very fast and extremely easy to use. It is small enough to carry in a lab coat pocket. Once the test is completed, the clinician drops it into the holding cradle and downloads the test to a printer or PC for storage. At the moment, the Interacoustics PC-based OAE product is less popular because it is relatively new and has had less market exposure. Interacoustics will continue to look at adding more features and is currently releasing an OtoRead interface to its popular OtoAccess database program. This feature will enable clinicians to combine clinical data from other Interacoustics instruments into a single patient file.

David Adlin,
national sales manager,
Maico Diagnostics, Eden Prairie, Minn

The ERO?SCAN Otoacoustic Emissions Test instrument, introduced in 1998, has been a best seller for a decade. It was the first truly handheld device with broad application as a screener and a full diagnostic instrument. It is designed for use by many health care professionals. Testers choose the handset or the remote probe, which allows for head movement without compromising accuracy. Settings and protocols can be customized for advanced users. The PC-based software for data collection, the portable printer for immediate recording of test results, and a lightweight carrying case are popular accessories. Newest on the horizon is the ERO?SCAN Pro, recently introduced by Maico. It is a new platform including tympanometry. DPOAE, TEOAE, and tympanometry tests are performed from a single probe, permitting screening or a full test battery with the press of only one button. The Pro offers two new printout formats: Quick-print to PC printer and Quick-print to PDF. These options provide an easy-to-obtain, professional 8.5 by 11 printout and a simple interface to electronic health record systems. A four-frequency ipsilateral acoustic reflex test will be added to the Pro system in 2009.

Maico distributes the ERO?SCAN, which is produced by Etymotic Research Inc, Elk Grove Village, Ill.

Lee VanMiddlesworth

Lee VanMiddlesworth,
US sales and marketing,
Otodynamics Ltd, Hatfield, Herts, UK

Thirty years ago, the audiological world was stunned by the discovery of OAEs by Dr David Kemp. During the next 10 years, Otodynamics was established, and developed and released the first commercially sustainable OAE analyzer. Landmark instruments soon followed. Otodynamics continues that tradition, transforming the world of portable OAE testing. The groundbreaking Otoport family of handheld products is designed around a state-of-the-art multiprocessor platform delivering quality OAE measurement with incredible speed and “gold-standard” accuracy. Impressive features are the longer battery life, increased patient storage, a comprehensive PC interface (OTOLINK), wireless printing, and a first in this category, bar code and RFID chip scanning available for ultrafast data entry. Combining this power in a lightweight design with easy, intuitive operation and informative graphics, the Otoport is available in three firmware packages customized for the screening environment. Whether it is the Otocheck’s (TEOAEs or DPOAEs) simplicity for basic screening of newborns or pediatrics … the Otoport Screener offering fast TEOAE screening with increased data and configurability … or the Otoport DP+TE for fast, easy-to-use TEOAE and DPOAE screening with basic two-level clinical testing for follow-up, the Otoport family can be ordered to fit clients’ needs. The powerful Otoport Advance offers true clinical OAE testing supported by a wide range of programming options. New capabilities will be added later in 2009, including Optimized DP Growth and contralateral suppression tests.

Practitioners/dispensers weigh in on our questions:

  • What brand/type of OAE screeners are you using?
  • What do you like about those products versus other types?
  • Have you tried other types?

Diane M. Taylor, audiologist,
coordinator of the Newborn Hearing Screening Program,
NYU Langone Medical Center, Tisch Hospital, New York

Taylor is the audiologist in charge of the universal newborn hearing-screening program at the hospital.

Since inception of the program in 2001, we have been using the Otodynamics Echocheck. We liked it, but its weak points were the fragile pins that the connectors had. We sent probes and Echochecks back for repair constantly, but I do have to say we had 30 people using them and not all were careful. We also had access to loaner screeners when more than one was out for repair. Also, the life span of the Echocheck (I was told) is 5 years, and ours are still working 8 years later. We just tried a loaner Natus Echo-screen. It was faster than the Echocheck, and I liked the fact that you could see the status in relation to time. The probe head is very heavy and can be difficult to keep in the ear, but we were impressed. We are also going to trial the Otodynamics Otoport.

Matthew S. MacDonald, AuD

Matthew S. MacDonald, AuD,
senior audiologist,
Strong Audiology, University of Rochester Medical Center, Rochester, NY

We screen 7,000 to 8,000 infants annually (well babies and NICU babies). Infants first receive a transient-evoked otoacoustic emission hearing screening, which is later repeated if they fail (unilaterally or bilaterally). Infants who do not pass the second TEOAE screening immediately receive an automated ABR screening. Currently, we are using the Otodynamics Echoport ILO292 USB-1 system in all of our nurseries. We chose the Otodynamics system because of its robust construction, manual control of signal-reject level, connectivity to PCs, and replaceable probe-tip couplers. We evaluated several other handheld TEOAE screeners by GSI and Interacoustics, but preferred the real-time manual control of the signal-reject level and ultimately found their data-entry interfaces too cumbersome. Further, the ability to service/replace the probe is critical when screening large numbers of infants.

Christine Eubanks, PhD

Christine Eubanks, PhD,
assistant director and director of audiology,
Chattering Children, Richmond and McLean, Va

Eubanks was formerly director of audiology at the John Tracy Clinic in Los Angeles.

At JTC, there is a school-screening program where we did OAEs and tympanometry on the kids who were not consistent or were too young for behavioral screening. We used both the Maico Ero-Scan, and the Interacoustics OtoRead handheld screeners—they are essentially twins, except that the Maico has a probe on the handle so it can be used like a gun. I never used it that way because I worried that if a child jerked his head, he’d get poked in the ear, but other screeners loved it. I preferred the long probe cord; the child could move around a little more and you could put the unit on the table and use both hands to steady the child and insert the probe. I have also used desktop-computer-driven OAE equipment, such as the GSI 60, but ultimately felt that not being tied to the desktop and having the freedom to move the equipment from place to place were too valuable—though it worked well and was fine if the child was asleep anyway, as in an ABR. We had considered units where the data could be downloaded to a computer, but in most school-screening situations pass/fail was enough information and it never seemed worth the expense. I know that there have been attempts to combine tympanometry and OAE in the same unit; that would be handy, but I suspect that the reason it has taken so long to implement is that the technologies are tricky to integrate and so I would be leery of the potential repair issues.

Judy O’Rourke is associate editor for Hearing Review Products. She can be reached at [email protected].

David T. Kemp

In this issue of Hearing Review Products, the focus is on OAE screeners—and that’s a major application of OAEs that everyone will be familiar with. But in their 30-year history, OAEs have found applications right across audiology.

The American Academy of Audiology is hosting a special Audiology Research Conference (ARC) in Dallas on April 1 titled “Otoacoustic Emissions: Improving Practice Through Science.” I am really looking forward to this meeting because the organizer, Brenda Lonsbury-Martin, research professor of otolaryngology at Loma Linda University, has brought together the leading experts on a whole range of key OAE topics. You will hear about where OAEs come from in the cochlea (still a battleground), see myths about what OAEs can and can’t tell us well and truly exploded, and learn how to make accurate measurements, how OAEs can give early warnings of noise-induced hearing loss, how the brain controls the ear, and how children win the prize for the largest emissions. There’s more to OAEs than simply screening—and there’s more still to come!

The fact is OAEs are our “direct line” to the cochlea hair cells and are invaluable in all branches of diagnostic audiology, to objectively monitor changes in the ear caused by disease, noise, drugs, or surgery; to assess neuropathy so that overamplification can be avoided; to explore how the brainstem acts on the cochlea, and how the cochlea regulates its own sensitivity. The challenge to researchers today is to tap that rich resource of information about the sensory mechanism and make it accessible to audiologists in everyday practice. Distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) date back to the first years of OAE research. We need to break through the “stimulus barrier” and learn to “talk” to the cochlea in a different way with stimulus sequences that extract much more information.

Ten years ago, a common question was “How can OAEs estimate hearing threshold more accurately?” Today we realize that is the wrong question and that OAEs tell us quite different things and are complementary to threshold measurement. Of course, for the time being, we are limited to those “classic” OAE tests that have changed so little in 30 years—DPOAEs and TEOAEs. They illuminate the cochlea through two slightly different windows. TEOAEs are more sensitive to the “amplification” side of hair cell function, and DPOAEs more responsive to their “signal compression” function. Both tell us if outer hair cells are actively processing the stimulus. Both are great for newborn screening provided they are used correctly. DPOAEs cease to be sensitive to mild losses if the stimulus level is too high. That’s not good for newborn screening, but it is great in the clinic for assessing the severity of outer hair cell loss. TEOAE testing has lots of advantages for newborn screening and also for the detection of minute changes in inner ear condition—but they are not effective for frequencies much above 5kHz. That’s just fine if you are screening for hearing that’s more than adequate for speech and language development, but not if you are looking for high-frequency hearing losses.

Some Backstory…

For a glimpse into the early stages of OAE development, read the tribute honoring Poul B. Madsen, legendary pioneer in audiological diagnostics and founder of GN Otometrics’ Madsen Electronics division, penned by Hans Kunov, PhD, professor emeritus at the Institute of Biomaterials and Biomedical Engineering, University of Toronto, and Yuri Sokolov, PhD, president and CEO of Vivosonic Inc.

Visit: www.hearingreview.com/issues/articles/2007-11_07.asp.

Both tests have their place, but you have to know your OAE technology to get the most out of them. Lots of audiologists are so used to assessing OAE signal-to-noise ratios in order to validate a screening pass, that they forget that it’s the sound pressure level, the absolute intensity in dBSPL, that is the physiological measure related to the strength of cochlear activity. It’s true that standards in OAE assessment are a long time coming, and this is partly due to the high variance in OAEs between ears—which we have yet to understand. But remember that the 30dB range of OAE intensities we commonly see is no more than the 30dBHL range we call “normal” in the audiogram (-10 to +20), and unlike the audiogram, OAEs only inform us about “fairly” normal functioning ears. But as we all know, many of today’s fairly normal functioning ears will be tomorrow’s hearing aid wearers; if we could learn to predict which ears those will be, and how to protect them, it would be a major step forward in audiology.

I’m sure research will achieve that soon, and I believe that OAEs will play an important part in bringing it about.

David T. Kemp, PhD, FRS, is the founder of United Kingdom-based Otodynamics Ltd and past recipient of the ARO Award of Merit and the ASHA Distinguished Service Award for his work on OAEs. Otodynamics specializes in otoacoustic emission instruments and offers a full range of screening, diagnostic, and research OAE systems.