A student asked,

What is the relationship between the SPL dB scale and HL dB scale?

Good question. I’ll bet there are lots of hard of hearing people that are unclear about the differences between those two scales, and often treat these two terms as though they are interchangeable and mean the same thing—if they even wonder about those acronyms on their audiograms.

When audiologists measure your hearing, they measure your hearing in units called decibels (dB). The catch is that there are several decibel scales. Thus, in order to be meaningful, your audiologist indicates which decibel scale she used. The two most commonly used scales are the SPL (Sound Pressure Level) and the HL (Hearing Level) scales.

Sound meters are calibrated in dB SPL. This makes total sense because the condenser microphones used in sound meters are sensitive to changes in sound pressure in the air, just as our ears are. In contrast, audiometers are calibrated in dB HL, not in dB SPL like you would think would be done. This begs the question, “Why not calibrate audiometers using the SPL scale and forget about the HL scale?”

Here’s the reason why. Our ears do not hear equally well at all frequencies. If our ears heard all

frequencies of sound equally well, then we wouldn’t need the HL scale.

Our ears do not perceive low- and high-frequency sounds as well as they do sounds between 500 and 4,000 Hz. For example, the faintest sound a young person with normal hearing can hear at 2,500 Hz is 0 dB SPL. In contrast, at 20 Hz (a very low frequency sound), the sound needs to be much louder at 72 dB SPL in order to just faintly hear it. At the other end of the frequency spectrum, a very high-pitched sound at 15,000 Hz needs to be increased to 20 dB SPL in order for you to just detect it.

Thus, normal hearing, if plotted on an audiogram using the SPL scale, would be a curved, wavy line and look like the bottom line in Fig. 1. Since this line is both curved and somewhat wavy, it would be difficult to readily tell on an audiogram how much hearing loss a person has by frequency.

It would be ever so much easier to visualize the degree of hearing loss if normal hearing showed as a flat, straight line set at 0 dB on the audiogram. Then, any deviation from this line would indicate the degree of hearing loss.

This is the reason why they developed the HL scale. The curved SPL scale is normalized so that it becomes a flat, straight line at 0 dB. (We call this normalized SPL scale the HL scale.)

Using the HL scale, normal (“perfect”) hearing is a straight line across the top of an audiogram. When your audiologist tests you, any deviation from the 0 dB HL line indicates a hearing loss if it falls below the 0 dB line. (By the same token, if your hearing deviates above the 0 dB line, you have better than normal hearing at that frequency.)

To convert SPL readings to HL readings, audiometers are calibrated to add a specific amount to each frequency tested. This amount varies by frequency. For example, at 125 Hz, it adds 45 dB, while at 1,000 Hz it only adds 7 dB. Likewise, at 4,000 Hz it adds in 9.5 dB, while at 8,000 Hz it adds in 13 dB.

The result is that now your audiogram readily shows your hearing loss graphically in dB HL, rather than you trying to mentally visualize the degree of hearing loss if it were plotted in dB using the SPL scale.

The Americans with Disabilities Act (ADA) gave disabled people the right to bring their service animals with them into public places and on public transportation.

Unfortunately, this soon became abused as it didn’t take long before people were defining various animals as their service animal—so there were “service” pigs, monkeys, birds, snakes, horses, etc. as well as dogs accompanying their “masters” into public places, and no one could do anything about it.

Now the government has issued new regulations defining exactly what a service animal is.

Part 36 Nondiscrimination on the Basis of Disability in Public Accommodations and Commercial Facilities (as amended by the final rule published on September 15, 2010) Authority: 5 U.S.C. 301; 28 U.S.C. 509, 510; 42 U.S.C. 12186(b).

Subpart A – General § 36.101 Purpose.

The purpose of this part is to implement title III of the Americans with Disabilities Act of 1990 (42 U.S.C. 12181), which prohibits discrimination on the basis of disability by public accommodations and requires places of public accommodation and commercial facilities to be designed, constructed, and altered in compliance with the accessibility standards established by this part.

Under Section 36-104 (Definitions) it reads:

Service animal means any dog that is individually trained to do work or perform tasks for the benefit of an individual with a disability, including a physical, sensory, psychiatric, intellectual, or other mental disability. Other species of animals, whether wild or domestic, trained or untrained, are not service animals for the purposes of this definition. The work or tasks performed by a service animal must be directly related to the individual’s disability. Examples of work or tasks include, but are not limited to, assisting individuals who are blind or have low vision with navigation and other tasks, alerting individuals who are deaf or hard of hearing to the presence of people or sounds, providing non-violent protection or rescue work, pulling a wheelchair, assisting an individual during a seizure, alerting individuals to the presence of allergens, retrieving items such as medicine or the telephone, providing physical support and assistance with balance and stability to individuals with mobility disabilities, and helping persons with psychiatric and neurological disabilities by preventing or interrupting impulsive or destructive behaviors. The crime deterrent effects of an animal’s presence and the provision of emotional support, well-being, comfort, or companionship do not constitute work or tasks for the purposes of this definition.

There is now only one exception to the rule that only dogs have the right to accompany their masters into public places. That exception is given to miniature horses (even though they are not recognized as service animals. Here is the pertinent part of the regulations.

Section 36.302 (c) (9) reads:

(9) Miniature horses.

(i) A public accommodation shall make reasonable modifications in policies, practices, or procedures to permit the use of a miniature horse by an individual with a disability if the miniature horse has been individually trained to do work or perform tasks for the benefit of the individual with a disability.

(ii) Assessment factors. In determining whether reasonable modifications in policies, practices, or procedures can be made to allow a miniature horse into a specific facility, a public accommodation shall consider –

(A) The type, size, and weight of the miniature horse and whether the facility can accommodate these features;

(B) Whether the handler has sufficient control of the miniature horse;

(C) Whether the miniature horse is housebroken; and

(D) Whether the miniature horse’s presence in a specific facility compromises legitimate safety requirements that are necessary for safe operation.

(iii) Other requirements. Sections 36.302(c)(3) through (c)(8), which apply to service animals, shall also apply to miniature horses.

Pretty well everyone gets hiccups from time to time. This is normal. Usually the hiccups go away in a few minutes. However, sometimes the hiccups persist for hours or days or weeks, and rarely, months or years.

When you hiccup, your diaphragm and nearby muscles contract, causing you to briefly gulp air. Within 35 milliseconds, the glottis at the top of your windpipe slams shut, producing the characteristic “hic”.

Hiccups are caused by a stimulus (normally an irritation) to either the vagus or phrenic nerves. When this happens, your brain sends a message via the phrenic nerve to hiccup.

The most common cause of long-term hiccups is damage or irritation to the vagus or phrenic nerves that serve the diaphragm. Incidentally, the vagus nerve also supplies nerve function to your eardrums. That is why anything that irritates your eardrum can also cause extended hiccups.

It could be something as innocuous as a hair touching your eardrum or an insect deep in your ear canal. For example, a 27-year-old man complained to his doctor that he’d been hiccupping for four days. The doctor looked into his ear and saw a hair tickling his eardrum. As soon as the doctor removed the hair, his hiccupping stopped.

Furthermore, anything that touches your eardrum can cause it to “flutter” as it rapidly retracts from contact with any foreign object and then relaxes again—which brings it in contact with the object again. This produces a fluttering kind of tinnitus. It feels somewhat similar to having a live insect flapping his wings in your ear canal.

This fluttering tinnitus can also result from a piece of wax touching your eardrum. So, if you were cleaning out your ears with a Q-tip and subsequently noticed a fluttering feeling in your ear or ended up with hiccups that won’t go away, going to your doctor and having your ear canals cleaned out may be the simple solution to either of these problems.

A man asked,

I’ve come across a website that’s called The Hearing Fix. They say they have capsules (a herbal mix and so forth) that works really well at restoring hearing, money back guarantee, backed by university research. Do you know of such? Is such correct?

You are not the first person to ask me this question. It’s always good to be cautious when you read claims that sound too good to be true—because they usually are—but they often have a grain of truth in them. I think this is the case here as well. Let me explain.

First, www.thehearingfix.com website is long on hype and short on facts. For example, on the home page there is a picture of a man dressed up as a doctor who is quoted as saying, “I believe that daily use of The Hearing Fix is the perfect way to ensure that one has the best possible hearing. I recommend it to everyone.” Notice, that there is no name given. The man who said this is either not a doctor, or doesn’t want his name associated with something he said. You have to wonder why.

Furthermore it claims, “The Hearing Fix: #1 rated hearing loss treatment”. Who rated this? Where’s the proof? Show us where it says this. The truth is that few people even know about this product—so how can it be the No. 1 rated hearing loss treatment?

Second, notice that there is supposedly a lot of research, but not a single source is cited. Rather there is just the hype, “Clinically supported Science from the universities of Florida, Michigan and Washington. The active compounds found in The Hearing Fix are supported by clinical research and have been cited in over 29 scientific studies.” It sure wouldn’t hurt to have a page that lists this information so people could check it out for themselves. This would give more credence to these claims.

Third, notice that this product is a food supplement. (I certainly have nothing against good food supplements!) As such, they are not allowed to make any claims for this product. Read their “Important Notice” on the home page, “The Hearing Fix is a dietary supplement designed to promote healthy hearing. It is not intended for use or treatment of any disease. Always use hearing protection.” and “These Statements have not been evaluated by the food and drug administration. This product is not intended to diagnose, mitigate, treat, cure or prevent any disease.” (emphasis mine)

So how can they claim, “The hearing fix is a revolutionary hearing loss treatment scientifically engineered to help protect and restore ones natural hearing abilities. This amazing product is a natural remedy to almost all causes of hearing problems including:

• Noise induced hearing loss
• Tinnitus
• Sensorineural hearing loss
• Presbycusis
• Conductive hearing loss
• Sudden hearing loss”

Fourth, notice that there is a paucity of information on the people behind this product. In fact, there is nothing available. When they “hide” this information, you wonder what else they are hiding. A good rule of thumb is that you should not buy from websites that don’t give a physical address, which this site doesn’t.

In contrast, look at any of my websites. There you will find my name, address, phone number, FAX number, email address, etc. and information about me. I have nothing to hide, and I want people to be able to check up on me to see if I’m genuine or not.

That’s the bad news.

Now for the good news.

The Hearing Fix is made up of a number of herbals (and I’m definitely in favor of taking herbals rather than drug) and amino-acids and related compounds. Here are a number of them and what they can do for you. (The following information comes from my herbal and other reference books—not from this website.) As you can see, none of these are “bad” things. In fact, they are all “good” things.

• The main herbal is Milk thistle (Silybum marianum)—300 mg.—which helps protect from the effects of free radicals, and boosts the body’s production of glutathione by 35%
• Grapeseed extract—100 mg. Grapeseed contains powerful antioxidant compounds called procyanidins
• Dandelion extract—100 mg.—is high in Vitamin A
• Scutellaria baicalensis—50 mg.—is a broad-spectrum antimicrobial that inhibits some viruses
• Schisandra chinensis—50 mg.—is another strong antioxidant, and also helps improve brain efficiency
• Barberry (Berberis vulgaris)—30 mg.—is a natural antibiotic used by herbalists in the treatment of ear infections
• Turmeric—30 mg.—is packed with the antioxidant vitamins A, C and E
• Celidonium majus—10 mg.—fights viruses, bacteria, fungi, tumors and inflammation
• L-Glutathione—100 mg.—this is the body’s most powerful antioxidant and zaps free radicals
• N-Acetyl-Cysteine (NAC)—100 mg.—is an amino acid that your body uses to make glutathione. Since glutathione is not well absorbed when taken by mouth, taking NAC is a better approach in helping your body increase its supply of glutathione
• L-Carnitine—50 mg.—is derived from the amino acids Lysine and Methionine. It plays an important role in such things as energy production, enhancing cellular energy in the brain and improving mental performance (from which we could all benefit)
• L-Methionine—20 mg.—is one of the 8 essential amino acids, and is a powerful antioxidant

Now, what does all this mean in relation to hearing loss. The US military and other researchers have been studying ways to protect military personnel from hearing loss caused by exposure to loud noise. They found that loud noise causes the production of free radicals in the inner ear. (Incidentally, taking prescription drugs, or eating fried foods, for example, also causes an excess of free radicals.) When these free radicals zap a hair cell, it either damages or kills it, resulting in permanent hearing loss.

If something could neutralize the free radicals before they zapped the hair cells, then hearing could be preserved. With that in mind, they turned their attention to antioxidants. Since glutathione is the most powerful natural antioxidant, they developed a “pill” that contains glutathione and associated amino acids. By taking these “pills” before going into battle, and again after the battle, they found that, to a large extent, the hearing of soldiers taking this treatment was preserved.

Coming back to The Hearing Fix, looking at the ingredients I’ve listed above, notice that many of them are antioxidants. Thus if you expose your ears to loud sounds, take drugs or eat foods that produce free radicals, these antioxidants will work to zap the free radicals, and thus help preserve your hearing. As a side benefit, if you preserve your hearing, you have a much better chance of not having annoying tinnitus either.

Also, notice that various of the herbals have antibiotic properties that can help protect your ears from the ravages of viruses and bacteria—again preserving your hearing, and by reducing ear infections, reducing the severity and frequency of conductive hearing losses.

So the bottom line is that The Hearing Fix, although short on facts and long on hype on this website, appears to be actually quite a good product. It’s missing a couple of important minerals such as zinc and magnesium that are also important for good ear health.

Taking The Hearing Fix won’t restore your hearing if you’ve lost it in the past, if its due to genetics, etc., but by promoting good ear health, and providing powerful antioxidants and antibiotic functions, it can help you maintain healthy ears, and help prevent further hearing loss caused by living in our noisy world.

Now that you realize what this product can and cannot do, you may choose to take this product and see whether you notice any benefits to your ears.

As near as I can tell, none of the ingredients are harmful to either your body or your ears, so the worst thing that you could expect is that your health improves along with preserving your hearing.

If you take this product, and assuming you cannot detect any change to your ears and your hearing, you can always ask for your money back—and get back an extra 10% back in the process according to their website. So it looks like you win either way.

_____________________________

Update January 21, 2011

The company that produces  “The Hearing Fix” recently changed its formula so what I wrote above about its ingredients is no longer valid. The new list of ingredients includes:

• Vinpocetine—a synthetic compound derived from the lesser Periwinkle plant (Vinca minor). It is supposed to increase blood circulation in your brain.
• Dimethylaminoethanol (DMAE)—a precursor for acetylcholine. Acetylcholine is a key chemical in neurons (nerve cells) that acts as a neurotransmitter, that is, it carries information across the synapses between adjacent neurons.
• Choline bitartrate—a member of the Vitamin B complex group. It helps increase the acetylcholine neurotrantmitter levels (see previous ingredient).
• Glycine—one of the non-essential amino acids that helps create muscle tissue and converts glucose into energy.
• Alpha lipoic acid—a natural antioxidant made by the body.
• L-cysteine—a naturally occurring amino acid.
• Pregnenolone—the basic steroid compound in your body that your body naturally produces and uses as the building block for all the other steroids it produces.
• Pyridoxine—basically Vitamin B6.
• Methylcobalamin—one of the natural forms of Vitamin B12.
• Folate—a natural form of Vitamin B9. Folic acid is the synthetic form.
• Ascorbic acid—a form of Vitamin C and acts as an antioxidant.
• Magnesium—needed to help protect your ears from noise damage. If you are around loud noise, it depletes your ears of the magnesium it needs.

I have my doubts that this formula is better than the previous one, but it is certainly different. The former formula was geared to protecting your ears from the effects of loud noise, while this one seems just to be promoting good ear health.

Like the above formula, I don’t think this new one will cause any problems to your ears, but I question how much change it will make, if any, if you are already following a good diet.

They still have their money-back guarantee, so if you try it and it doesn’t do anything for your ears, you can get your money back.

The Deaf and Hard of Hearing Consumer Advocacy Network (DHHCAN) has just released their new Consumer Action Guide on Air Travel.

This guide is based upon the recent update of the Air Carrier Access Act regulations issued by the U.S. Department of Transportation in May 2009, during one of the most comprehensive overhauls since the Act was enacted in 1990.

The Air Carrier Access Act (ACAA) sets out requirements for disability access at airports and on airlines. These ACAA rules give protection from discrimination by:

• Prohibiting U.S. and foreign airlines from discriminating against passengers on the basis of disability
• Requiring airlines to make aircraft, other facilities, and services accessible
• Requiring airlines to take steps to accommodate passengers with a disability

“Today’s travelers need information from the minute they arrive at the departing airport until they leave the destination airport. It is crucial that they have prompt access to information once they self-identify that they are deaf, hard of hearing or deaf-blind,” says Barbara Raimondo, author of the DHHCAN Air Travel Action Guide 2009 and a mother of two deaf children.

The DHHCAN Action Guide on Air Travel is available online both as a summary and as a full document. This 7 page report is easy to read. The first page is a summary of the full text on pages 2 to 7.

One of the nice things about this Act is that it applies not only to all US airlines, but to any airlines flying to or from US soil.

Source: TDI News Release November 13, 2009

Perhaps some of you might be interested in taking part in the below survey. Note: it is limited to children living in the USA. This survey comes from the University of Washington in Seattle, WA. The study is looking for parents of children who are hard of hearing or deaf. Here’s the blurb.

“My name is Nancy Hanauer and I’m a study recruiter with the University of Washington. Our university is conducting a Quality of Life Study for Children and Youth Who are Deaf or Hard of Hearing and we’re hoping you’d be willing to share information about the study with the families in your program. We’re looking for deaf and hard of hearing children and youth ages 5 to 18 and their parents for participation in the study (US residents only). Learn more about the study here.”

 Recently as I was surfing the web, I came across an audiological web site that blew my socks right off. This audiological practice provides an impressive array of services to hard of hearing people, but what really arrested my attention was that this particular audiology practice had an “Ototoxicity Monitoring Program,” something that I have been saying for years that audiologists need to implement, but until now I had never seen advertised on any audiologist’s website.

The thing that really got my attention was that they tested hearing right up to 20,000 Hz—the upper limit of human hearing. In contrast, conventional (normal) hearing testing is only done to 8,000 Hz. Thus, conventional hearing testing misses the early stages of hearing damage from drugs, which typically first occurs at the highest frequencies the person can hear.

By the time hearing loss has progressed down to 6,000 to 8,000 Hz where it can be detected by conventional audiological testing, it is much too late to do anything about preventing hearing loss. By that time, drugs have very likely permanently destroyed the person’s high-frequency hearing.

Upon seeing this website, I couldn’t let this pass, I just had to phone Dr. Lisa and find out more about her high-frequency hearing testing program and why she was doing it.

It turns out she used to work for a cancer clinic where she did high-frequency hearing testing to monitor the effects of the highly-ototoxic drugs given to cancer patients. Thus, she knows the importance of high-frequency hearing testing. Therefore, when she moved into private practice, she purchased an audiometer that could test the high frequencies and set up her own monitoring program.

Incidentally, for years, when I have talked to audiologists, they kept telling me that normal audiometers only test to 8,000 Hz. and that it requires special audiometers to test hearing to 20,000 Hz, and that such audiometers were not readily available. Well, I have news for them. Audiometers that test to 20,000 Hz are indeed readily available. The one Dr. Lisa uses is the Grason-Stadler GSI-61 audiometer. Hard of hearing reader, you might suggest to your own audiologist that they get one of these audiometers so they can monitor your high-frequency hearing.

Another unusual thing I noticed about her website that really pleased me was that she carries all sorts of assistive listening devices (ALDs). Few audiologists do this, so I needed to find out why she places such emphasis on ALDs. It turns out Dr. Lisa is hard of hearing herself, and well knows the value of such devices. In fact, her hearing got so bad that she now has a cochlear implant. So not only is she an audiologist, she is also one of us hard of hearing people at the same time.

Her Colorado Tinnitus and Hearing Center carries a wide selection of ALDs including “Amplified telephones; Cellular phone adaptors, Personal Infrared and FM Television amplifiers; Personal Pocket talkers; FM Systems for students; Sonic alarm clocks with bed vibrator; Door bell alerts and much more!”

If you live near Denver, Colorado you might want to stop by for your audiology needs. You can reach the Colorado Tinnitus and Hearing Center by phone at 303-534-0163, or visit their website at http://www.tinnitusandhearing.com/services2.asp.

From time to time, the issue arises as to what we (people with a hearing loss) call ourselves. Many of us refer to ourselves as “hard of hearing”. One person with a hearing loss commented: “It’s a stupid expression if you ask me. Hard-of-hearing makes no sense.”

Everyone is free to have their own opinions. However, I am also free to disagree with the above opinion. You see, in MY opinion, the expression “hard of hearing” is actually quite accurate. Here’s why.

Hearing (or more accurately understanding what we hear) is hard. If all we needed was more volume, we would be “soft of hearing,” and hearing aids and assistive devices would give us the extra volume we need. Then hearing would be effortless.

However, amplification isn’t enough. We still often can’t understand what people are saying in spite of the extra amplification. This is because we have less than perfect discrimination. Thus a lot of words are “fuzzy” and sound much the same to us. It takes a lot of effort to try to make sense of what people are saying under these conditions.

For example, we have to strain to hear. We have to go though a lot of mental gymnastics in order to figure out what they might have said. We have to concentrate on the person’s face to speechread. Then our brains have to put together what our eyes see, what our ears hear, what we know about the topic and what we know about the structure of the language. No matter how you slice it, all this is hard work. So yes, in a very real sense, we truly are hard of hearing. No wonder we are wiped out at the end of the day. All this hard work exhausts us.

So I am quite happy to use the term “hard of hearing” as it accurately portrays what I go though every day of my life.
 

A lady wrote:

My hearing loss has been described as “an air gap in the bone.” Whatever do they mean by that?

What you really mean to ask is, “What is an air/bone gap?”

When your audiologist does the pure tone hearing testing (the series of beeps at different frequencies and intensities), the “air” refers to “air conduction” testing using earphones, and the “bone” refers to the “bone conduction” testing using a bone oscillator (vibrator) placed behind your ear on the mastoid bone.

If you have a sensorineural hearing loss (meaning inner ear loss) both the air conduction and the bone conduction results will be similar.

However, if you have a conductive loss (meaning a middle ear loss) then your bone conduction testing results will be better than the air conduction results on your audiogram. This difference between the two lines or your audiogram is called the “air/bone gap”. Thus, the gap is only on your audiogram; it is not a physical gap in some bones in your head.

You could also have both a conductive and a sensorineural hearing loss at the same time. They call this a mixed loss. In this case, you will also have an air/bone gap on your audiogram.

Here’s an easy way to separate the doctors who are truly trying to help you from the doctors that just run “patient mills.”

It’s based on the astute observation of J. Apley who, back in 1978, wrote:

Doctors who treat the symptom
tend to give a prescription.
Doctors who treat the patient
are more likely to offer guidance.

No matter what condition you have–whether its hearing loss, balance problems, tinnitus, or anything else, if you want to get better, you and your doctor need to root out the source of the problem, not just cover over the symptoms and whitewash it.