HEARING AID FITTINGS TODAY vs YESTERDAY; IS IT BETTER?

Compression did not begin with digital hearing aids

By Theodore H. Venema, PhD
Author of Compression for Clinicians: A Compass for Hearing Aid Fittings, Third Edition

My career in this field began in 1987 as a new audiologist at The Canadian Hearing Society in Toronto. All hearing aids were analog and provided linear gain, although a few compression circuits floated around too. These used output limiting compression, with its high knee-point and high compression ratio. The knee-point was adjustable, which in turn adjusted the maximum power output (MPO). It was a way to limit the MPO without the use of “peak clipping,” which caused distortion.

Wide dynamic range compression (WDRC) entered the scene with a cannonball splash right around 1990. The action of the outer hair cells (OHCs) was now understood by clinicians as being distinct from that of the inner hair cells (IHCs). As we all know today, the OHCs enable the IHCs to sense soft incoming sounds below around 50 dB SPL. WDRC was thus seen as a rather “intellectual” type of compression, in that it electronically sought to imitate the role of the OHCs. With its low knee-point and a low compression ratio, the focus of WDRC is to elevate the “floor” of hearing sensitivity, rather than to limit the MPO or “ceiling” of loudness tolerance. It is no coincidence that otoacoustic emissions—also known to arise from the action of the OHCs—suddenly emerged as part of clinical practice.

Compression in today’s digital hearing aids hasn’t really changed all that much from then. We continue to use both output limiting compression and WDRC. The point here is that the analog hearing aids of that time (late 1980s, early 1990s) used either one type of compression or another. Clinicians had to know their compression types because their hearing selection for any client depended on this knowledge. Manufacturer fitting software did not yet exist. Today’s digital hearing aids are programmed exclusively by software. Once the audiogram is entered through Noah, the hearing aid signal processing is automatically programmed to provide whatever compression is deemed necessary. We’ve become “dumbed down,” because we no longer have to know how to apply the compression. The manufacturer fitting software takes care of all that!

The cables, the cables, the cables…

The emergence of the cables actually began in the very late 1980s, with the first “programmable” analog hearing aids. A cable from a computer (or more often a handheld programming device) was plugged into a socket on the faceplate of an ITE or on the backside of a BTE. Adjustments were made via this “digital screwdriver.” This seemed like a really “cool” alternative to manually adjusting hearing aid settings by trimmers, trim pots, potentiometers, whatever they were called. We simply turned these clockwise or counterclockwise, in order to raise or lower the MPO, gain, low-cut, high-cut, etc. I used to laugh that if the original settings were somehow lost, one could simply set all the trimmers halfway; that way, one could maximally be only half-wrong.

Back to the cables, it is truly amazing just how many different ones exist, even for the product lineup of any one manufacturer! This issue is not at all new, and I am not the  first to complain about that. I must admit to feeling a little odd though, when hanging a weird looking hook around the client’s neck with cables connected to the hearing aids positioned in the client’s ears. The next step is to sit in front of the computer, hoping and praying the manufacturer’s fitting software will read the hearing aids.

Manufacturer fitting software, fitting software, fitting software…

Fitting software emerged at the end of the analog era (mid 1990s) and flourished with the advent of digital hearing aids in 1997. Of course, with each manufacturer, the fitting software is completely different. Oh, there are some similar traits among them, but the look, the feel, the labels, and also the quirks and exceptions, are different for each manufacturer.

Digital technology and software certainly do add flexibility; they also however, invite their best friend, complexity. There are so many parameters involved with fitting now: noise reduction amounts and types, directional microphones and associated polar plots, feedback suppression adjustments, linking binaural hearing aids, and don’t forget about the battery indicator beeps! It gets better; we in separate programs, make combinations of the above-said parameters, in order to specifically address various different listening situations, such as quiet, conversations, and traffic.

Has anyone seen ANSI? Where did it Go? Sometime during the late 1990s, with the advent of digital hearing aids in 1997, ANSI slipped away. It happened in the middle of the night. Since the 1950s for hearing aids, ANSI was intended to be a measurement standard for hearing aid hardware, which consists of the microphone, amplifier, and receiver (aka speaker). Add a few capacitors, resistors, inductors (and trimmers to adjust their behaviors), and you still have nothing but analog hardware. Such was the consistency of analog hearing aids. ANSI ruled in the analog land of hardware, but now fitting software rules. Quaint concerns about OSPL90, Reference Test gain, Harmonic Distortion, and Equivalent Input Noise have almost faded from view. Today it’s all about software. Most clinicians today never bother with ANSI because they are just trying to figure out the fitting software.

The dongles and Bluetooth paraphernalia…

On a semi-annual basis, the goals and deadlines of their product management cycles dictate that manufacturers must pound out new and updated products. The cacophony of their escalating product releases has become deafening. What’s more, hearing aids now come with all kinds of dongles, Bluetooth remotes and gadgets to be used with other devices that work with the phone, television, etc. Of course, these have to be “paired” together to work with the hearing aids. Despite the best efforts of manufacturers to explain things, it does make me feel a bit like “Ted the Cable Guy.”

Clients commonly come back to the office with bags containing unused cords, boxes, television streaming devices, and dongles. It can be quite difficult to get elderly people to make sense of it all! Bottom line: Clinicians today are still constantly “putting out fires,” much like they always did in the past.

Epilogue

It’s obvious that hearing aids today are far better than the squealing, beige “banana-shaped” BTEs of yesterday. The disappointing thing, however, is that the rate of client satisfaction has not risen at the same rate as hearing aid development and complexity. The unwanted byproduct from complexity is confusion, felt by both clinicians and clients.

We have made amazing strides in technology, digital algorithms, and features. The downside is that it has all come at a cost, literally and figuratively, to clients and clinicians. With all the recent progress, I’m not sure clinicians feel that fittings are easier today than they used to be. I also do not believe the monetary cost of hearing aids compared to eyeglasses is at all well understood by clients. Is anyone really surprised at the recent emergence of (and governmental support for) an alternative, namely, those low-cost personal sound amplification products, also known as PSAPs?

Talking Hearing Aids with Brian Taylor and H. Gustav Mueller

Brian_TaylorGus_Mueller TaylorMueller_2e_FDHA2E

Fitting and Dispensing Hearing Aids, a popular introductory textbook, has just been published in its second edition in September. We managed to listen in to a conversation between its two authors, Brian Taylor and H. Gustav Mueller, who were exchanging some thoughts regarding their new 2nd Edition.

BT:  You know Gus, when we wrote the first edition of this book, I remember us talking about the fact that there seemed to a fair number of professionals who maybe weren’t following Best Practice when they were fitting hearing aids.  We thought that it might simply be because they didn’t exactly know what was called for in Best Practice, or maybe it never had been laid out for them in an orderly manner.

HGM:  And we thought a book like ours might help . . .

BT:  Right.  Do you think it did?

HGM:  I’d certainly like to think so.  We sold a lot of copies, so that’s a good start!  But honestly, when I travel around, I don’t see as much change over the past five years as I thought might happen.  Let’s take pre-fitting testing for instance.  We have some great speech-in-noise tests available for clinical use like the QuickSIN, the BKB-SIN and the WIN.  We talked about all of these in the book, provided step-by-step guidelines, yet I just don’t really see an uptake—for some reason, audiologists and hearing instrument specialists seem to have a love affair with monosyllables in quiet, which really have little use for the fitting of hearing aids.

BT:  Maybe we’re expecting things to happen too fast.  I think it’s good we expanded that section on pre-fitting speech recognition testing in the current book—hopefully more readers will take notice.  And as you know Gus, I’ve always been a fan of the ANL.  I just saw that there has been over 40 articles published on that test in the past 12 years!  That’s another easy-to-do test, and it really provides information that you cannot learn by doing speech recognition testing.

HGM:  Part of Best Practice is picking the right technology for the right person.  I recall you spent a lot of time researching all the new technology that has come out in recent years for this 2nd Edition.

BT:  Things change pretty fast in that area.  I think we’ve added some great new sections on wireless connectivity, frequency lowering, and audio data transfer between hearing aids. Like the first edition, rather than getting into the intricate technical details of various features, we focus on how this technology benefits the patient. For example, in the chapter that covers wireless connectivity and audio data transfer between hearing aids, we write about how these new features enhance benefit in background noise, and how candidates are identified.

HGM:  And, of course, verification of the fitting is critical.  The best hearing aid in the world is no better than a PSAP if it’s programmed wrong.  I think our new section on speechmapping will be extremely helpful for people who are just getting started using probe-mic measures.  As we described, recent research clearly has shown that you can’t simply rely on what you see simulated on the software fitting screen.  As, of course, all those special features that you talked about, such as frequency lowering, need to be verified in the real ear too!

With all that said, however, we also know that verification alone is not enough to demonstrate to patients, their families, and even third-party payers that a new set of hearing aids is worth the investment—so, we can’t forget about outcome measures.

BT: Yes, Gus, it seems there are always a couple of new outcome measures to talk about. With all of the recent research on the impact of untreated hearing loss on other conditions, like cognitive function, social isolation, and overall mental health, we added a section on validated self-reports to measure the impact hearing aid use may have on these common conditions.  Even if you’re not inclined to measure those types of downstream outcomes, we added more detail on using the International Outcome Inventory for Hearing Aids (IOI-HA). As you know, many audiologists and hearing instrument specialists neglect to conduct any outcome measures. We cover the reasons this is a bad idea, and suggest, if you are only going to use one measure, it ought to be the IOI-HA.

HGM:  And you know, some people suggested that it was a little silly for us to use our chapter themes of country music, movies, wine tasting, baseball, and all the others, but I’m glad we kept that going in this 2nd Edition.

BT:  Me too.  Who said you can’t have fun and learn about hearing aid fitting at the same time?  After all, it’s worked all these years for the two of us!

 

AudiologyNOW! 2016 Author Signing Schedule

AudiologyNOW! attendees – Meet our authors and connect with experts in the field! Stop by the Plural booth (#301) for the following Meet the Author sessions: 


Thursday, April 14, 11:00 am – 12:00 pm
Meet Marc Fagelson, BA, MS, PhD 
Co-editor of Tinnitus: Clinical and Research Perspectives

Marc Fagelson   Tinnitus


Thursday, April 14, 3:00 – 3:30 pm
Meet Mark DeRuiter, MBA, PhD and Virginia Ramachandran, AuD, PhD
Authors of Basic Audiometry Learning Manual, Second Edition 

Mark DeRuiter   Virginia Ramachandran   Basic Audiometry Learning Manual, Second Edition


Friday, April 15, 11:00 – 11:30 am
Meet Ruth Bentler, PhD, H. Gustav Mueller, PhD, and Todd A. Ricketts, PhD
Authors of Modern Hearing Aids: Verification, Outcome Measures, and Follow-Up  

Ruth Bentler   H. Gustav Mueller   Todd A. Ricketts  Bentler_MHA.jpg

Congratulations to Ruth Bentler, 2016 recipient of the Jerger Award for Research in Audiology. 


Friday, April 15, 1:00 – 2:00 pm
Meet Anne Marie Tharpe, PhD
Co-editor of Comprehensive Handbook of Pediatric Audiology, Second Edition

Anne Marie Tharpe   Comprehensive Handbook of Pediatric Audiology

Congratulations to Anne Marie Tharpe, 2016 recipient of the Marion Downs Award for Excellence in Pediatric Audiology. 

2016 Awards and Honors

We are thrilled to announce the winners of the 2016 Plural Publishing Research Awards given in honor of the late Dr. Sadanand Singh, Plural’s founder. These two scholarships are awarded by the Council of Academic Programs in Communication Sciences and Disorders and the honorees and their faculty sponsors will be acknowledged at the annual CAPCSD meeting award banquet, in San Antonio, TX on March 31.

At the MS/AuD level, the award went to Chelsea Hull of the University of Nebraska-Lincoln. Working with advisor Dr. Sherri Jones, Chelsea is researching the impact of Sound Field Amplification (SFA) devices, specifically the REDCAT amplification system, on student academic outcomes and teacher perspectives of this amplification system on academic improvement.

CAPCSD Scholarship Chelsea Hull

Chelsea Hull                                                         Au.D. Student                                             University of Nebraska-Lincoln

At the PhD level, the award was given to Nancy Quick of the University of North Carolina. Under advisor Dr. Melody Harrison, the focus of Nancy’s research is on investigating the impact of underlying linguistic sources of knowledge on spelling among children with hearing aids, cochlear implants and normal hearing, utilizing a multilinguistic analytic approach.

CAPCSD Scholarship Nancy Quick

Nancy Quick, M.S. CCC-SLP               University of North Carolina at Chapel Hill PhD Candidate in Speech and Hearing Sciences, Class of 2017

Congratulations Chelsea and Nancy on your achievements!


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Guest Post: 4 Types of Hearing Tests You Should Consider

Our guest post this week comes from HEARING Life Australia and explains the benefits and uses of different types of hearing tests. The intention is to share this with your patients to help simplify the complexities in such a way that anyone can understand.

-Plural Team

 4 Types of Hearing Tests You Should Consider

conversationIf you often find yourself asking your loved ones to repeat themselves, find it difficult to follow conversations, or receive frequent complaints that you talk too loudly, it may be time to book a hearing test at your local hearing clinic.

Hearing tests employ a range of technologies that can determine your level of hearing impairment and whether you need to invest in a hearing aid. But with so many hearing tests available, it’s important to know which one is right for you.

Consider the following types of hearing tests:   

         1. Pure-Tone Testing

This hearing test will reveal the faintest tones a person can hear at various frequencies, from low to high. This test involves an audiometer machine emitting a range of beeps and whistles, called pure tones, with the participant responding to each sound.

When taking the pure-tone test, the participant may be asked to respond to the sounds through raising a finger or hand, pressing a button, or vocally affirming to indicate that a sound was heard.

The results of the test are plotted on an audiogram, a graph that charts the degree and type of hearing loss.

Pure-tone testing is a behavioral measurement that relies on patient reaction, and therefore is best performed on adults and children mature enough to cooperate with the test procedure.

         2. Speech Discrimination Tests

These tests involve an audiologist assessing the participants’ ability to hear speech, with the results also recorded on an audiogram. These tests may involve the participant having to repeat words that are said to them.

Hearing loss that comes with aging generally begins with individuals losing the ability to hear higher frequencies, so that certain speech sounds begin to sound confusingly similar. A speech test can measure the amount of experienced speech distortion.

In order to assess the participants ability to understand speech with background noise, speech testing may be conducted in a quiet or noisy environment. This test is typically used on older children and adults, and may be used to confirm the results of the pure-tone test.

         3. Auditory Brain Stem Response (ABR)

The ABR test provides information about the inner ear (cochlea) and the brain pathways required for hearing. For this test, electrodes are connected to the head in order to monitor the brain’s response to sounds. The participant lays still or even sleeps during the test.

This test can be performed on children, or those that might have difficulty with more typical behavioural methods of hearing loss tests.

         4. Online Hearing Tests

For an initial assessment at home, taking an online hearing test is a great way find out whether someone should seek further professional assistance. While an online hearing test is not intended to replace a hearing assessment with an experienced hearing care professional, it may assist in identifying whether hearing loss is an issue.

In order to undertake an online hearing test at home, it is necessary to have Internet access with the ability to stream sounds, as well as a pair of headphones. Before starting, it is important to check that the computer volume is on and that the surrounding environment is quiet.

Online hearing tests may consist of different components, such as an audio screening which will test the respondents’ ability to hear sounds. An online test may also include questions that require honest answers regarding the person’s hearing ability. These tests will typically generate a score or recommendation that can be used as the starting point to assessing hearing health.


About the Author:

hearinglifeThis post was written by HEARINGLife Australia, one of the world’s leading networks of hearing care professionals. HEARINGLife has provided hearing services to Australians for over 70 years.

HEARINGLife aims to provide sufficient information about hearing loss, hearing aids and hearing tests by providing independent advice and to provide customers with options in a way that is easily understandable. More information can be obtained from HEARINGLife’s website and social media profiles: Google Plus | Facebook  | Twitter

 

Feature Article: Technology helps patients with hearing loss thrive

Seilesh BabuBy Seilesh Babu, M.D., Michigan Ear Institute

Hearing loss is one of the most common conditions affecting otology patients whether as a newborn or aging patient. Hearing loss can significantly impact one’s ability to communicate leading to reduced quality of life, isolation, and even depression. Seeking medical help to assist with this hearing loss can be the biggest obstacle for many patients who do not want to acknowledge a hearing issue. However, if the problem is properly managed with hearing aid assistance or surgical therapy, improvement in the patient’s quality of life including anxiety, depression, frustration, and social isolation will be positively impacted.

In our practice at the Michigan Ear Institute, we see thousands of patients annually with hearing loss concerns in all age groups. Some of unilateral hearing loss and many have bilateral hearing loss, ranging from mild to profound. Unilateral hearing loss can be caused by not having an ear canal form (canal atresia) or, from nerve damage of unknown etiology. These patients have several options to improve their hearing such as using CROS hearing aids, bone anchored devices, dental implanted devices, or surgical repair of the poorly formed ear canal in the case of atresia. Many patients have significant improvement in their hearing in various situations using these technologies and surgeries.

Recently, a patient of ours received a scholarship from Cochlear Americas, the global leader in implantable hearing solutions. This scholarship recognizes bone anchored device and cochlear implant recipients who have shown academic accomplishments as well as a commitment to leadership and humanity. Using the technology of hearing devices, patients are able to complete advanced academic pursuits despite having hearing impairment that may have proven to be an obstacle. We are proud to be a part of this successful path for this patient who is currently enrolled in a Ph.D. program.

Hearing technology continues to improve. Advances in hearing aids have occurred with smaller, more powerful processors and noise canceling technology, as well as masking technology that treats tinnitus or ringing in the ear. Middle ear implants provide a surgical treatment option for patients who do not want to wear conventional hearing aids. Cochlear implantation has revolutionized the ability to treat patients with complete hearing loss either as a newborn or for patients in their 80s.

baby_hearing_aidChildren born with complete deafness are able to be treated with a cochlear implant with near normal function from speech and language development to academic performance. Adults with late onset profound hearing loss are also able to obtain a cochlear implant in order to maintain excellent quality of life, independence, and social interactions. Some elderly patients diagnosed with Alzheimer’s disease may in fact be suffering from severe hearing loss that needs to be diagnosed and managed.

In the future, advances in stem cell development and treatments will improve the quality of life of hearing loss sufferers. In addition to these new technologies, it is the collaborative effort of otologists, audiologists, and speech-language pathologists in treating patients with hearing loss that continues to have a positive impact in the lives of these patients every day.

Hearing Aid Awareness Week

October 3-10 is Hearing Aid Awareness Week! Here at Plural we have a wide range of titles that are applicable to this topic.

“Fitting and Dispensing Hearing Aids” by Brian Taylor, AuD, and H. Gustav Mueller, PhD is just one great resource.

This extremely practical and engaging book logically takes the reader from beginning to end of the entire hearing aid selection and fitting process. The chapters sequentially provide the reader with the essential knowledge needed to fit modern hearing aids, along with links to handy websites for further study and reference.

 

For our full list of titles, check out our website

 

Fitting and Dispensing Hearing Aids

Just released—everything you need to know about fitting and dispensing hearing aids! Experts Brian Taylor, AuD, and H. Gustav Mueller, Ph.D. provide a consistent overview of the fundamentals of the entire hearing aid selection process with step-by-step guidelines, covering both the art and science of hearing aid fitting.

This extremely practical and engaging book logically takes the reader from beginning to end of the entire hearing aid selection and fitting process. The chapters sequentially provide the reader with the essential knowledge needed to fit today’s hearing aids, along with links to handy Web sites for further study and reference. Order your copy today!