The Story So Far

I've been working on my grant outline for the last week or so and managed to flesh out a couple of the sections. These are ultimate first drafts and need serious editing but I can't edit if I don't have something written down, right?



Objective
The main purpose of this project is to explore the possibility of alternative noise exposure in young adults. Much attention has been paid to personal digital media and music consumption, but we have not been so diligent with occupational noise and the effects of cumulative exposure to sources not labeled harmful by OSHA. If we can identify possible sources or a true cumulative effect, we can warn those young adults who feel monitoring their music consumption is all they need to do to protect their hearing.




Statement of Importance and Relation
Points of Importance:

• Young adults often fall through the cracks of audiologic assessment. Loss that begins after elementary school may go undetected until it has caused a significant disparity or delay in a student's coursework.
• Young adults who feel they are protecting their ears may be falling short in areas other than music consumption (wind noise in the car, noisy work environment, etc.).
• People of all ages could benefit from a study of non-occupational, non-leisure noise exposure; wind on a car window, traffic noise, etc.
• This research opens the door to refute the idea of presbycusis in facor of sociocusis, which would be a more accurate term in many cases.
• Broaching the topic of young adults and hearing loss would help to remove the stigma from both hearing loss and misunderstandings during conversations, and hopefully allow high schools students to seek help with hearing their professors (through assistive listening devices) when they enter college.
• This study would give people the opportunity to adjust their work and home environments to be safer. For instance, if a restaurant owner is unaware that the average SPL in their establishment is 70dB, he or she cannot take measures to reduce noise exposure for the employees. If the owner of the establishment is warned of the dangers of noise exposure, he or she can take measures to reduce the noise, by turning down music, monitoring the levels of 'walkey-talkies', etc.

How does this research fit with your educational and career goals?
I approached Dr. Brockett last semester because I was frustrated with a lack of direction. I have known for a year, now, that research is the place for me but I was unsure how to pursue such a goal in my undergraduate education. I explained my desire to apply for an undergraduate research grant as a way to practice for my future career, and he graciously agreed to help me out. This grant would be instrumental in helping me to achieve invaluable experience for my graduate education and the rest of my life.

Sections Remaining:
Abstract
Procedures/Methods
Timeline for Completion
Cooperation/Collaboration
Dissemination of Results
Literature Cited (This just needs to be brought together, the grunt work is already done.)
Budget and Justification

I will try to flesh out the Procedures and Timeline sections this weekend. I'll need Dr. Brockett's help for fleshing out the Dissemination of Results section... Maybe a videoconference is in order?

And more!

Survey of College Students' MP3 Listening: Habits, Safety Issues, Attitudes and Education Alicia Hoover, Sridhar Krishnamurti. American Journal of Audiology (2010)
This piece was about a short survey of college students at San Diego State University. A third of the students surveyed reported using their MP3 players 5-7 days per week, and two-thirds reported they used them at least 3 days a week. Only half of the respondents reported their volume was set at or less than half. Nearly 20% and 25% reported listening to the MP3 players while riding in a car and on the bus (respectively). Over 90% of the students reported turning the volume up to overpower background noise, and more than a third reported sometimes listening to their MP3 players at full volume in certain situations.
Also, over half of the students expressed irritation with being advised to reduce their listening volume and less than half were aware of their ability to limit the maximum volume on their MP3 players. Nearly 70% of the students were willing to turn down the volume on their MP3 players to protect their hearing.
The authors concluded that, "There is a need for more organized public education on safety issues associated with MP3 player use," and I totally agree! Not only do we need to warn teenagers about the hazards of incredibly loud MP3 players, but also educate them about signs of hearing loss, and overexposure.


Stress Pathways in the Rat Cochlea and Potential for Protection from Acquired Deafness Richard A Altschuler, et. al. Audiology & Neuro-Otology (2002)
This article was another scientific one, so I didn't understand it as much as I would have liked, but the basic idea is a discussion of Hsp70, the heat shock protein induced by noise, hyperthermia, and ototoxic drugs. It is produced, "...in response to stress and provides for protection, recovery and repair..." but, "...there can be a delicate balance between protection/survival and cell death pathways..."
I guess it boils down to the idea that our bodies try to protect themselves but can go a little overboard.


Comparison of Audiometric Screening Criteria for the Identification of Noise-Induced Hearing Loss in Adolescents Deanna K Meinke & Noel Dice (2007)
This article addressed some interesting changes to the 'standard' school of thought regarding young adults and noise-induced hearing loss. In younger children (6-11 years old), only 8.5% had noise-induced threshold shift as opposed to the older children (12-19) who showed a NITS in 15.5% of children.
The authors mentioned two studies regarding the noise notch beginning at 6kHz instead of 4kHz: Salmivalli (1979), who found that the 6kHz notch appeared twice as often as the 4kHz notch, and Axelsson (1979) who found that, "earliest audiometric changes can often be found at 6000 Hz" before they generalize to 4kHz. Since we don't screen at 6kHz (or sometimes even 4kHz, for that matter), we don't typically notice.
The importance of screening adolescents comes from some frightening statistics, including, "...37% of children with mild sensorineural hearing loss failed at least one grade." For older students, the feeling of invincibility can result in failing to get help and therefore suffering in lectures. I know this because I have experienced it firsthand.
The authors also listed a couple ideas for 'fixing' the problem, including the possibility of using a video game to test the hearing of the students. "Perhaps," the authors wrote, "the game could be designed to educate the student about NIHL while screening for the disorder at the same time." Way to multitask! :) The other recommendation the authors included was standardizing the screening techniques used for early identification, something I feel is long overdue.

Susceptibility of the Noise-Toughened Auditory System to Noise-Induced Trauma Roger P Hamernik & William A Ahroon. Hearing Research (1999)
I never really thought about 'toughening' the auditory system but after I found the article I was incredibly intrigued. The idea that we could potentially toughen our ears to protect us during onslaughts of noise is encouraging. Unfortunately, the authors found that there may be a 'toughening' effect, but only because a permanent threshold shift means that the ear isn't receiving as much signal. There was no protective effect from the 'toughening' exposure.
There are three other similar articles which arrived at approximately the same conclusion, they are:
Conditioning the Auditory System With Continuous vs. Interrupted Noise of Equal Acoustic Energy: Is Either Exposure More Protective? Ruth A Skellett, et. al. Hearing Research (1998)
Noise-Induced Hearing Loss in the Noise-Toughened Auditory System. William A Ahroon & Roger P Hamernik. Hearing Research (1999)
Effect of an Initial Noise Induced Hearing Loss on Subsequent Noise Induced Hearing Loss. Ronen Perez, et. al. Hearing Research (2004)

Last, but not least...
Presbycusis, Sociocusis and Nosocusis. Karl D Kryter. Journal of the Acoustic Society of America (1983)
Through several population-based studies, this article explains the basics of presbycusis, sociocusis and nosocusis in our country. According to the article, presbycusis starts at age 20, possibly earlier. (My belief is that it is sociocusis at this age, not presbycusis.) Boys were found to have more prevalent/severe presbycusis than girls, presumably due to their preferred social habits (guns, trucks, etc.). The authors mention that, "Hearing sensitivity is increasing with maturation up to the age of roughly 16 years." and that sociocusis begins soon after that. So basically, the age at which teens are using their iPods the most is the age that sociocusis begins... Hmm...
The authors also explain the study of the Mabaan tribe in Sudan, which is hailed as a 'noise-free' population study. Unfortunately, there were inconsistencies with the method which call the results into question. If the error was in calibration, the results could still stand that there were no gender differences in hearing sensitivity, and that, "Presbycusis progresses at a slower rate in a noise-free society than it does in industrialized, relatively noisy societies." (Ultimately, this is sociocusis!)

Wrapping Up The Summaries

As I was choosing which articles I'll use for my outline, I realized that I have several articles I read and forgot to summarize. Here they are!

Mechanisms of noise-induced hearing loss indicate multiple methods of prevention. Colleen G Le Prell et al. Hearing Research (2007)
This article outlines a lot of different methods for prevention of noise-induced hearing loss, including studies of antioxidants, steroids, and vasodilators (among others I couldn't understand). Although most of the article was beyond my comprehension level, I did gather that scientists are coming close to finding prevention methods for noise-induced hearing loss both immediately and up to weeks after exposure.
In terms of antioxidants, the idea came after Halliwell, Gutteridge, and Evans discovered "...that intense metabolic activity alters cellular redox state and drives the formation of free radicals... In excess, [free radicals] damage cellular lipids, proteins, and DNA, and upregulate apoptotic pathways." So essentially, the noise is over-energizing the metabolic activity which causes breakdown of the auditory system. Using an antioxidant helps to reduce or eliminate the permanent threshold shift in a noise-exposed system. Interestingly enough, the temporary threshold shift is not affected by use of antioxidants.
I found it fascinating that the authors explained, "The finding that dietary supplements reduce NIHL is of particular interest given their easy over-the-counter accessibility; however, therapy with any single micronutrient may need to be initiated days to week in advance of noise exposure to obtain clinically meaningful results." That's alright! We should all be getting more nutrients to begin with. I never thought that vitamins could reduce the effects of harmful noise. No wonder our society is becoming more affected by noise pollution; we're getting less healthy, too! This is an important factor to keep in mind for young children whose diets are still determined by their parents.
It's not directly related to the topic of this research, but the authors made the point that, "...[Neurotropic factors] have been shown to be extremely effective at preserving neural survival in the absence of surviving hair cells." This screams cochlear implant application to me and would be a good point to remember when that time comes in class!


Effect of Long-Term Noise Exposure on the Developing and Developed Ear in the Rat. Sharon Freeman, et, al. Audiology & Neuro-Otology (1999)
This article was fascinating! I have always thought that young ears are more sensitive than fully-developed and 'toughened' ears. This article (and its sources) proved that idea to be false. As the authors wrote, "...exposure caused greater long-term changes in hearing in the adult compared to the young noise-exposed rats, although histology showed greater damage to hair cells in the younger animals." This floored me! What causes less functional loss but more cellular damage? Is the younger ear just more able to adjust and compensate?
Also blowing my preconceptions out of the water was the response to the idea that babies in the womb are protected from sound. The authors wrote, "...more recent measurements in humans and sheep, using a hydrophone, showed that lower frequencies were not attenuated at all and may even be enhanced by about 5 dB, whilst higher frequency sounds are attenuated by 10-20 dB only." Very interesting!


More to come this evening. I hit a wall!

Good News and Bad News

The bad news first: I've found it incredibly difficult to find anything directly related to my research topic. Of course there is plenty of research on noise exposure and music exposure in young adults, but I have not been able to find anything which suggests that presbycusis is really sociocusis in disguise. I'm not sure how I will handle this, but I know it will work out.

The good news: I was struggling with a lack of structure for my outline over the past month. Every time I sat down to write, all I could think about was how open it was. Do I start by making up a conclusion, listing my methods, reviewing my literature or what? So, in a fit of angst, I revisited the application papers for the Undergraduate Research Grant and discovered that an outline structure was already provided! All that's left, now, is to fill it in. I can do that.

I feel confident once again. It's going to be a good semester. :)

Great News!

I started college as an ASL major and had a vested interest in learning as much as possible, so I came into ISU with quite a knowledge base of Deaf Culture and American Sign Language. I was able to petition out of the Deaf Culture 100-level course but was encouraged by my advisor to take Deaf Culture 256: Culture and Community.

But after half the semester, I felt I had learned nothing new and decided to drop the course and petition it.

My first petition was denied due to lack of documentation of my knowledge, so I re-petitioned with an essay I'd written on the juxtaposition between Disabled and Non-Disabled status in the Deaf Community, especially in relation to the Americans With Disabilities Act. Apparently it was still not enough and Dr Turner asked me to take the final exam from the course.

I was livid after taking the exam, because so much of the information was proprietary -- it was not in the textbook (Journey Into the DEAF-WORLD by Ben Bahan et. al) and therefore not readily available to me. I felt like I had been cheated somehow.

But today I received news that Dr Turner has accepted my petition and I won't have to take the course. This is great news! Now I'll have that extra room in my schedule to fill with psychology courses and research. This fall, I'm in a research methods psychology course and I'm very excited about it.

Anyway, just thought I'd share my excitement! I feel vindicated, almost.

More Bad News

I wore the dosimeter for a full day. Drive to work, work-day, and drive home. I didn't even hit 25% dose. I'm beginning to think the dosimeter is broken.

It might be important to note that when I was wearing headphones at work (during my music listening/PBS viewing) and at home (during my Modern-Warfare 2-ing), I couldn't use the dosimeter. This is good and bad -- it is good because it allows for any significant findings to be attributed to work conditions, bad because I can't factor everything in and get the true picture.

I will be purchasing a Sound Level Meter in the near future so as to have as much information about my auditory surroundings as possible. Until then, I will be putting the dosimeter on the shelf and buckling down on my secondary research so I can meet my deadline.

I'm Not Broken!

I've known about Jung's personality test for a while, but the last time I took it was in high school. I don't remember what I got, but I reckon it was different than it is now. I feel like I've grown into myself over the last several years and the results I got are almost spot-on.

I turned out to be an INTJ. An Introverted iNtuitive Thinking Judging personality. I've included my favorite parts of what that means below. The relationships part is what surprised me the most and made me very happy to discover. I'm not broken, I'm just an INTJ!

"When it comes to their own areas of expertise -- and INTJs can have several -- they will be able to tell you almost immediately whether or not they can help you, and if so, how. INTJs know what they know, and perhaps still more importantly, they know what they don't know."

"Personal relationships, particularly romantic ones, can be the INTJ's Achilles heel. While they are capable of caring deeply for others (usually a select few), and are willing to spend a great deal of time and effort on a relationship, the knowledge and self-confidence that make them so successful in other areas can suddenly abandon or mislead them in interpersonal situations. This happens in part because many INTJs do not readily grasp the social rituals; for instance, they tend to have little patience and less understanding of such things as small talk and flirtation (which most types consider half the fun of a relationship). ... Perhaps the most fundamental problem, however, is that INTJs really want people to make sense. This sometimes results in a peculiar naivete', paralleling that of many Fs -- only instead of expecting inexhaustible affection and empathy from a romantic relationship, the INTJ will expect inexhaustible reasonability and directness."

"Decisions come easily to them; in fact, they can hardly rest until they have things settled and decided. But before they decide anything, they must do the research. Masterminds are highly theoretical, but they insist on looking at all available data before they embrace an idea, and they are suspicious of any statement that is based on shoddy research, or that is not checked against reality."

As an INTJ, I highly value accurate truths, even if they don't benefit me. I remember as a kid even correcting my friends because they tailored the truth to benefit themselves. Ugh.


More journals are coming. I found some interesting pieces on potential conditioning and toughening of the auditory system in lab animals but I want to read all of it before commenting and summarizing.

Diversions

When I make a list of the few non-necessities that I couldn't live without, one of them is always 'diversions'. By that, I mean the things that make me a multidimensional person.

I've been taking photos part-time as a self-sufficient hobby since Sophomore year of high school, and while my work isn't as artsy as I would like it to be, it's definitely commercial which works in my favor. I mostly do senior portraits, but in anticipation of doing my first paid wedding gig outside of my family, I volunteered my services at my wedding-partner's friend's wedding.

The results reminded me once again that I can't let myself get too sucked into one thing. I need to keep photography around as a nice diversion and to prove I'm more than just my collapsible file folder.

Some Answers! (Hopefully.)

So I have grown up in an interesting financial situation. My family makes plenty of money, but most of it gets spent on medical bills despite our great insurance. My father had at least one surgery on his neck and I've had two separate surgeries for my tonsils and my adenoids (thank you, Dr. Van der Graaf, for providing cold, faceless, incomplete surgeries), along with medications and such along the way and my year+ of therapy for my arachnophobia.

In short, my parents didn't have any money saved up for me to go to college, but they make too much for me to get any free government assistance, so they've been taking out Parent Plus loans to pay for my tuition and living expenses. The thing about Parent Plus loans is that they tack on lots of interest.

I'm mostly independent. My parents still help out with my gas and give me a small allowance each month, but I work and live on my own, and I have since moving out in 2007. So lately, I've been wondering about declaring independent status on my tax forms, because it may help me out with getting legit aid from the government.

Because I have no idea who to ask, I decided to ask "Judge Josh" from www.givemescholarships.com what he thinks the pros and cons of declaring independent status would be.

One obvious one is that I don't think I'd be able to be on my parents' insurance, but even at that point I'm not positive. I'm still young enough to count, and I'm in school. I need some guidance from someone who knows the system.

Hard At Work

Here is the second dose (get it?) of my summaries. This puts me up to date for all the articles I have read so far. Time to gather more! :)

1. Recreational noise exposure and its effects on the hearing of adolescents. Part II: Development of hearing disorders. Ester C Biassoni et al. Int'l Journal of Audiology (2005)

This study was a follow-up to the one in Argentina looking at the undue amount of hearing loss in young adults. As much as has been found about NIHL, the author writes, “...the auditory system is much more adaptable than currently assumed, therefore it recognizes the danger of intensive sound and adapts to the situation by reducing its sensitivity.” Even so, the research shows that young adults are exposing themselves to extreme noise in settings such as discotheques and concerts.

An interesting point that this study raised was that there is data which indicates, “...that the supersonic components of the music spectrum may have substantially contributed to the damaging effects of the exposure.” Sound we aren't even measuring could be greatly-affecting how much we're damaging our hearing. This allows for the possibility of sub-damaging levels of noise to still affect us.

Later on, the authors explain that the group with the worst thresholds (those deemed to have 'tender ears') exhibited elevated thresholds in the 8000-16000Hz range, extending lower into the conventional range of hearing. This, the authors state, “...could act as an early predictor of future development of hearing loss in the speech-understanding frequency range,” which is of most concern to clients.

Knowing that this loss happened between ages 14 and 17, this study provides evidence for the need to test students before they are pushed out into the 'real world,' when they can still gain help through the school system. There is also evidence for a hearing conservation (hearing loss prevention) program in the schools, perhaps blended into biology courses. It would also be helpful to limit the noise level in loud places, such as concerts, 'discos'/bars, etc. Even reducing noise levels at rock concerts from 117 dBA (equivalent to the discotheques in the other studies) down to 106 or 103 dBA would be helpful, due to the 3 dB exchange.

2. Characteristics of the audiometric notch as a clinical sign of noise exposure. David McBride and Sheila Williams. Scandinavian Audiology (2001)

This study was an evaluation of 1,600 audiograms (634 noise-exposed employees, each with two ears), the purpose of which was to investigate variability in the noise-induced hearing loss 'notch'. Traditionally, the first sign of noise-induced hearing loss is at approximately 4KHz, where the audiogram develops a small notch that gets deeper and wider as the damage continues. The authors chose three raters (an otolaryngologist, and audiometrician, and an occupational physician) to interpret the audiograms and determine whether or not the dip is related to noise exposure. The three features the interpreters looked for were the frequency at which it occurred, the depth, and the shape of the curve.

I found an unexpected piece of information while reading this article. The first rater (the ENT) classified 26% of the audiograms as NIHL, whereas the occupational physician classified 68% as NIHL, with more notches identified at every frequency and no specific criterion for depth or shape in mind as he/she rated. This is evidence for why occupational audiologists are needed as opposed to unrelated professions which are slated for an audiologist's job. I think this would be an important statistic to show in advocacy situations. Not only are we better-trained, we can save the companies money by not over-referring!

Either way, the high variability suggests that audiometric shape cannot be used as a method for diagnosing noise-induced hearing loss. As Alberti (1997) states (as quoted by the authors), “This supports the contention of Alberti, who has long been of the opinion that audiometric shape may only be a guide, and not a major diagnostic factor for, for NIHL.”

3. Supplement: Program for the Conservation and Promotion of Hearing Among Adolescents. Mario R Serra et al. American Journal of Audiology (2007)

This supplement was another piece in the “Recreational Noise Exposure and Its Effects...” done in Cordoba, Argentina and involving 14-year-old students in a semi-longitudinal study over three years. As the authors state, there were two noticeable findings: “1. There was a higher tendency of more sensitive ears to be affected at an early age... 2. The efficacy of audiometry in the extended high-frequency range was an early predictor of hearing loss.” The latter is probably the most important clinically, but the former is important to keep in mind as we discuss the issue of noise exposure in young adults. Some sources state that young ears are less fragile, and others state that fragile ears are more susceptible while young.

This article taught me a few things about noise exposure that I hadn't quite learned yet. Namely, the authors explain, “While TTS typically resolves within a few hours or a day after exposure, there is no agreement among researchers whether repeated TTS bears a risk of permanent threshold shift.”

4. Effect of a hearing protection campaign on the discotheque attendance habits of high-school students. Viktor Weichbold, Patrick Zorowka. Int'l Journal of Audiology (2003)

This was an ambitious study with high hopes that unfortunately failed to deliver. The goal was to pilot a hearing loss prevention program in six high schools in the Italy/Austria area called “PROjectEAR” and hope that it changed young people's opinions about hearing protection and loud noise. There were four 45-minute sessions spread over 3 days which presented several different approaches to protecting one's hearing. An interview was conducted post-campaign with 136 students although all of the students in the schools participated.

While the percentage of students who attended discotheques frequently lowered from 34% to 24% after the campaign, statistical analysis does not support the idea that there was a significant change. The authors state that, “..the changes observed in our sample may be due to the random variation rather than to a systematic effect of the hearing protection campaign.” In addition to that discouraging finding, less than 4% of the students took the advice to use ear plugs or other hearing protection in the discos.

The authors explain that there is no control group for this study because there was too much information-sharing between students participating and those were not. Also, although, “...the campaign had no important effect in inducing hearing-protective behaviors in pupils when attending a discotheque,” one of the other studies found that students were willing to take more 'regeneration breaks' after the program and have the discotheques reduce their sound floor, so perhaps that is an area to target.

A quote I really liked that I wanted to include for the sake of aesthetics is, “At this point, a tragic irony becomes obvious. The pupils experienced the negative effect of bad hearing on communication when they tested earplugs for hearing protection in the discotheque. Being annoyed about the impaired communication, they dismissed the earplugs.”

5. Noise exposure levels from personal stereo use. Warwick Williams. Int'l Journal of Audiology (2005)

This study aimed to look at worst-case scenarios of personal media players, such as listening in the presence of relatively loud background noise. In this case, the background noise was approximately 73.2 dB, but varied from 71.1 to 76 dB. Fifteen females and forty males were asked to participate in the study (mean age 23.6 years), which meant allowing their headphone output to be measured and filling out a short survey of their listening habits. The average volume turned out to be only 79.8 dB, but approximately 25% of the population was still estimated to be “at-risk,” by listening to music over 85 dB.

Also of note is that the males (the larger group) listened to their music at 80.6 dB on average as opposed to females ,who listened at 75.3 dB. Perhaps if more people were studied, this average would sneak up?

The authors state in the conclusion that, “While some individuals do expose themselves to significant risk of noise injury by using earphone levels at high settings, the data collected in this study does not indicate that for the majority of typical users there is a significantly increased risk of hearing loss due to PSP (personal stereo player) use alone.” Unfortunately, those people who may lie on the boundary line are at risk in other areas of their lives because people who listen to their music loudly are more likely to listen to their television loudly, etc.

6. Effects of Exercise and Noise on Auditory Thresholds and Distortion-Product Otoacoustic Emissions. Shannon Hooks-Horton et al. Journal of American Academy of Audiology (2001)

This study isn't totally connected to the research I'm doing, but I found it hilarious that the authors actually address, “It is also the case that ovarian and contraceptive cycles may play an additional role in TTS shift in females, however this factor was not controlled in the present study,” and that the TTS shift for ovarian cycles was actually investigated by two different studies: Petiot and Parrot (1984) and Hori et al (1993). How funny is that!

Oh, and by the way, the authors found that there is no significant connection between exercise and noise-susceptibility.