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Musician Speaks Out on Hearing Aids!

My name is Rick Ledbetter. I am a bassist, composer and music producer. I have a computer based music composition and digital audio production studio, and, I have been in music six I was six. I have a formal music education an learned audio production from some of the best in LA. (If you are wondering, I work with headphones and use another persons ears when I need it) My loss is an inherited late onset, and is stable. I am in 53, and my father passed away with only about ten percent of his hearing left. About twelve years ago, my hearing started to degrade over a span of three years; it has stopped deteriorating, and is more or less stable. I first purchased a set of analog hearing aids, but they were useless, and they wound up in a drawer. I later went to analog aids with a K-Amp, which were much better, but not very good for music.

About two years ago, I upgraded to digital CICs on the advice that they would be superior to my analog aids for sound reproduction. My long-suffering audiologist (and I hope he is reading this and knows how much I appreciate him for putting up with me) tried his best, but simply did not have an acoustical environment to set up the aids for hi fi music reproduction. The initial fitting sessions were hit and miss, and frustrating for both of us. Since I am familiar with music production, computers, and have a lot of sound generators, he was kind enough to let me borrow the interface on the weekends and let me learn how to adjust the aids myself. After about a year of trying to get the aids adjusted right, I finally switched off all compressors, NR, limiters, etc, set the output limiter to hard limit (in my brand of aids, even though the limiter is set to 0db, it is still on, no matter which type of limiting- multiband, broadband or hard limit, is chosen) and set the EQ for the best music fidelity the aids could reproduce. Since these aids are two channel, I have the second channel set up for speech in difficult situations, with a minimum of upper end compression. Channel one is my music channel, and I use it almost all of the time.

While I was learning to adjust my aids, I accumulated a bunch of observations, experiences and ideas, and I am passing them on in the hopes that someone will profit from my situation. Digital aids do not have a "sound" any more than a home stereo has a "sound". OK, a home stereo is dependant upon the speakers, but that is less of an issue here. The "sound" is dependant on the EQ (tone controls) and various compressors, noise reducers, speech enhancers, and limiters in the aids. The reason aids sound different is because of the settings made when they are shipped. Think a car stereo with the bass turned all the way down- you have to adjust it to your liking.

Most aids manufacturers make their aids with limiters permanently on, and others use different types of compressors, but, by and large, the digital sound amplification process is the same from company to company. Aids are created, and the dispensers are trained, from the standpoint of speech recognition. This was an acceptable model with the older analog aids, but this model does not apply to digital aids, which are high fidelity sound reproduction devices, and should be fitted as such. The aids makers often do not provide enough information for a dispenser to adjust the aids beyond a series of templates based upon the wearers hearing loss and optimum speech recognition, and I know of dispensers that are displeased with the makers for not telling them everything they need to know about fitting the aids. I believe that the makers could be doing a lot more to rectify this, but Audiological association could be doing more to bring its members up to speed and making sure they have the equipment and knowledge to fit digital aids. I believe the makers should provide more training and certification for dispensers... And I do not mean taking a multiple choice test to see if they know the product literature and can parrot the figures, but making sure that the dispenser knows what all of the controls are, what they do and how they interact. And most importantly, what the aids sound like. The dispenser needs a real worl acoustic environment to set the aids, with good speakers to reproduce sound, a strong enough amplifier to recreate real world decibel levels, and an acoustically adjusted room in which to fit the aids. Face it, you can not get an idea of what your aids will sound like when you are sitting in a hard walled office, listening to a 3 inch computer speaker play back a tinny recording of a music clip. I have had a number of HOH people contact me in total frustration because their dispenser is not achieving the right adjustment and is attempting to characterize the patient as "difficult"- hardly a constructive approach. I believe this attitude, and any other statement or action that damages the patients confidence, and reflects on the dispensers incompetency, and any dispenser who treats the aid wearer with disrespect and condescension should be barred from selling aids.

The person with a hearing loss is already trying to deal with a sense of isolation and inadequacy without having the person they depend on to fit the aids contributing to it. The statistics showing that a lot of aids wind up in a drawer does not always reflect upon the wearer- it also shows the inability of the dispenser to properly fit the aid. Dispensers are accustomed to working with older, uniformed aid wearers, and they are not always prepared to answer specific technical questions about the aids. In my experiences of listening to the complaints of many other aid wearers, there are dispensers who tend to get defensive (I am lucky- mine did not) when questions are asked that are beyond their training. This generates an atmosphere of distrust when the aids wearer realizes that the dispenser does not know the answers or the solutions. It is odd that a degree in audiology does not mean adequate training in the fitting of hearing aids. The curriculum treats aid fittings as a course elective of minimal hours. Therefore, the aids dispenser must get training from the hearing aid maker, and a process of self-education. Many dispensers feel that the aids makers are not teaching them enough about the digital aids and how to fit them, beyond the use of templates. If you go to the web sites for aids, and you will find a lot of vague superlatives and good web site design, but no data. And no prices either, but that is for another day. And if you go to the support sites for the HOH, and you will have to search long and hard for information about how to choose an audiologist, what questions to ask, and practical information about digital aids and their fitting.

The following is my two cents worth, comparing digital aids to quality sound amplification: The most important feature of hearing aids is the number of EQ bands (tone controls), and the ability to reproduce both low and high end frequencies, and I mean from as low as 125Hz to as much as 10Khz. The low end can be helped by a bigger vent, but at the cost of risking feedback; most aids ignore bass loss, and make no attempt to amplify it until around 250hz. To give you an idea, the sound of a drum kitÕs bass drum, also called a kick drum, happens from 80 Hz to 120Hz., and an electric bass has a frequency range that begins at 32 Hz. An upright bass has a low frequency at 42Hz, but the body will create a thump an octave under that. Got the idea? If you have an aid with a small vent, needed to reduce feedback potential, you will block out the low frequency sounds, so, somehow, the low end needs to be reproduced. I would choose an aid with at least ten bands and the widest frequency for those bands as the first requirement, and discount a lot of speech enhancers and noise reduction in favor of a quality multi band compressor, and output limiter, sparingly used. The problem with using compressor- expanders, limiters, etc., is that they reduce volume differences- kind of like what happens on the radio- all sounds are pretty much at the same volume. And this is not natural. Who wants to hear a songbird at the same volume as a passing Harley-Davidson? Granted that a hearing loss is marked by a narrowed range of difference between loud and soft, and a greater sense of perception in volume differences, but still, the aids should have a sense of difference in volumes. This, along with sight, is how we judge spatial placement and orientation.

Probably the hardest part of adjusting aids is translating sound into terminology: What is "tubby", "harsh", "shrill", etc. This is where the aids wearer has to pay attention to what the aids are reproducing, and be able to tell the audiologist. I found that the initial setting is close, and, once all of the limiters, enhancers, etc. are off, reducing 1KHz, 1.5Khz, and 3Khz, one notch each, then increasing 250Hz and 500Hz one notch will more or less get the aids to sounding "real". Here is a rough approximation of terminology of sound and frequency: Thuddy is 250Hz, Boomy is 500Hz, Muddy is 750Hz, Clacky is 1Khz, Harsh is 1.5Khz, Shrill is 3Khz, Piercing is 4Khz, Zingy is 6Khz. Please keep in mind that this wonÕt always be the same from wearer to wearer, but it is a start. And note that the EQ bands are interactive: if 3Khz is too shrill, but bringing it down loses too much treble, then bring down 4Khz and see if this helps. If you find that you canÕt hear consonants well, then reducing the lower frequencies will unmask them. The beginning point is always balancing the aids: a tedious process of making sure the eras are hearing frequencies well in both sides at the same time. I do this with the help of a sine wave generator in my studio, listening to one tone at a time, until they are balanced. I have found that I will misbalance treble and bass, but once the ears are hearing in left- right balance, it is a lot easier to raise or lower each frequency on both sides until the overall EQ curve is pleasing.

The aids makers have put so many "bells and whistles" in the aids that they have lost focus of what the aid is supposed to do- provide "normal" sound reproduction. Any music producer will tell you that you start with a good tone setting (EQ), to enhance the sound, and then carefully bring in the compressors and limiters, but only as devices to do what the EQ cannot do. They know that it is impossible to achieve the best sound while trying to adjust EQ, limiters and compressors all at the same time, because of the way they interact with each other. But the aids makers expect a dispenser to fit an aid with a generic template, which includes having all sorts of noise reduction, limiters, and compressors going at the same time In my personal experience of adjusting my aids, I have found that most of the noise reduction and compressor- expanders, et al., are of limited usefulness. I think they are more distracting than they are useful. I was bothered by their constant self adjustments- sounds disappearing, others getting louder, some appearing out of no where. I found that most of the offensive noise was generated by over boosting the speech frequencies. If those are over boosted, then limited, then enhanced, then all you are doing is slapping one band-aid on another. You must begin with a good sound.

And while I am on a tear- I believe that a CIC is the best choice, because it uses the outer ear to help the aid give the wearer a better sense of "real". Some seem to think the choice of a CIC is cosmetic, but, the deeper the aids microphone is in the ear canal, the better the sense of sound placement and what is "natural" will be. You are used to hearing with your outer ear shell, so why not make things easier and use it? I think that aids makers should figure out how to get the mike and speaker as far down in the canal as possible, even if the works have to be placed behind the ear. Setting the aids must be done in increments, to allow the brain time to adjust. This means making adjustments and seeing how they work in the real world, and the process is tedious can take weeks. Since the bulk of audiologists do not have a listening environment to set the aids, then the wearer must go through a long process of hit and miss. It would be much better for an aids maker to produce a loaner hand held adjuster, which the aids wearer could take home. From the aids wearers point of view, this means an adjustment can be made when desired, without the trouble of booking an appointment, and from the dispensers point of view, this reduces to number of follow up adjustments dramatically. And I think that finding the right setting can take as much as three months, and the wearer and dispenser should allow at least three days in between readjustments, and set the aid wearer on a regular visit schedule, more often at first, for fitting the aids. There is no reason that a wearer cannot learn to adjust their own aids, and likewise, I think that the interfaces should be made available for home adjustment for those who are willing to learn how. But we must educate ourselves about sound and our loss, so that we can relate to the dispenser what we need to hear in our aids. They can only guess, and if we canÕt describe what we need to change, they will have no way of finding it.

And finally, it is up to the aids wearer to educate him or herself about Digital hearing aids, their individual hearing loss, and what good sound is and how to achieve it. It will be frustrating and a test of your patience, but you must be patient- this will take time. It is not as daunting as it may seem, but it is necessary for you to be able to work with your audiologist / dispenser to achieve the best possible setting for your aids. And one big caveat here: what sounds good to one person does not sound good to another- whether we are talking about car stereo, hearing aids or even a concert hall. One I found the setting that I liked on my aids, I spent some more time tweaking the EQ for my personal preferences and needs. For instance, I like a bit more bass, so I had the 250Hz up a bit. For those that take it upon themselves to get their digital aids adjusted correctly, I hope that you are able to reach this point where you can fine tune your aids to your lifestyle- with digital aids, it is possible. Please excuse the redundancy in my musings- I am not much of a writer, but I hope I got some points across and managed to answer a few questions. If I can be of help, please feel free to email me. smalldog@triad.rr.comRick Ledbetter ©2002





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