Tuesday, March 8, 2011
I was floored that at one concert I went to, I hit 730% in 90 minutes! It may not be the primary purpose of this research, but it has definitely changed my opinion of hearing protection at concerts/musical events.
One of my bar readings was surprising as well. I didn't expect the sound level in the corner of the room to be reading in the 80s, but it did. I would venture to guess (I didn't have my Sound Level Meter with me) that it was about 10 dB louder near the bar, and considerably louder near the bathrooms where the speakers were.
Now that I am able to transfer the files, expect more preliminary reports as I get them!
Sunday, October 17, 2010
Friday, September 17, 2010
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.
Timeline for Completion
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?
Tuesday, September 14, 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!)
Monday, September 13, 2010
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!
Saturday, September 11, 2010
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. :)
Wednesday, July 21, 2010
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.
Tuesday, July 20, 2010
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.
Sunday, July 18, 2010
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.
Saturday, July 17, 2010
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.