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Welcome to the Recent Speeches Podcast presented by BYU Speeches, featuring inspiring new devotionals and forums given each week on BYU Campus. Be sure to check out our other podcasts by searching BYU Speeches wherever you get your podcasts or by visiting speeches BYU Edu podcast.
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I did ask for an 80 word introduction. I am thankful to be here today and share things that I've learned. I've learned so much from many of you, especially my family. As the son of a biology professor and an elementary school teacher and husband to an English teacher, I have been surrounded by educational excellence. I've also learned from willing and capable mentors from all over the world, and from current and former students. Finally, I've learned how much work it takes to put these events together and I am so grateful to all those who have made this forum possible. When I received the email telling me I'd been selected for this honor, I was off measuring rockets with my students. That night. I lay wide awake as my mind raced trying to make sense of what this meant my stewardship as a teacher, a mentor, and a disciple scholar. Since I could not sleep, I decided to listen to several Maeser Fellows Forum addresses. Prior award recipients made me pleased to know that their forums did absolutely nothing to cure my insomnia. Rather, a sense of inadequacy grew as I listened about masterful efforts to learn, to teach and to lift Imposter Syndrome is a real thing. And as I struggled to understand how I could now live up to what others thought of me, a feeling that has persisted. I actually felt like my career was over. But as I prepared this forum, I understood something new. For me, my feelings represented a form of noise that prevented me from feeling gratitude and determination to take what I've learned to bless my students, family, and others more deeply. Focusing on gratitude in the midst of Imposter Syndrome is a personal lesson from Noyes that I'd like to share. This does not mean that I've got everything with imposter syndrome figured out, though. Some have actually wondered why the Maeser Award is not hanging in my campus office. That's because it hangs just outside my bathroom at home. I mean, it deserves to be hung somewhere, and at least there I know it serves as daily motivation. Today's discussion is both physics based and metaphorical. My introduction referred to my current calling as primary chorister, which is the best calling ever. Anyway, I've been teaching my primary kids a song called My Own Sacred Grove, which applies directly to today's discussion. Its chorus begins, I will find my own sacred grove away from all of the noise in the world. As we talk about aspects and impacts of noise in the world, I encourage you to think about your own individual experiences with all forms of noise. Now, for some acoustics. An acoustic wave forms as the air is temporarily compressed by a sound source's movement. Because the air acts like a spring, this compression travels as a pressure wave. The sound we hear comes from these fluctuations pushing and pulling on our eardrums, beginning a fascinating chain of energy conversions that results in electrical signals being sent to our brain. Now, our ear doesn't respond as well to low frequencies. Frequencies less than about 20 Hz or fluctuations per second are infrasound. Our ears also don't respond very well to very high frequencies. Beyond 20,000 Hz is referred to as ultrasound. Now, as we listen twice to a frequency sweep over the full audio or audible range, pay attention to the screen behind me. As the noise spectrum changes from low to high frequencies, that spectrum will continue to play real time throughout the forum to help you visualize what you're hearing. While our ability to hear high frequencies naturally lessens with age, sorry to those confused by several seconds of silence just now, our hearing mechanism can be prematurely damaged if the pressure oscillations are too large. We need to be careful because our ears are incredibly sensitive. If you lightly take your thumb and index finger and rub them together near your ear, go ahead and do it. Your eardrum's displacement in hearing that sound is around the diameter of a hydrogen atom, 1/10 of 1 billionth of a meter. Yet you can hear that because of the huge range of sound amplitudes that our ears respond to. We use a logarithmic quantity known as the decibel. There are different types of decibels. A weighted decibels emphasize the frequencies we hear best for everyday sounds. This chart shows the a weighted levels of different sound sources from a whisper to gunshots and beyond. Now, every increase in 10 decibels or 10 dB means 10 times more sound energy. And additionally, a 10 dB increase corresponds to a doubling in our perceived loudness. So let's illustrate. The noise that you are about to hear will step in 10dB increments starting around a whisper. Hopefully you're able to hear those increases in loudness. If not, get your hearing checked. Returning to the chart. Anything more than 85 dB can cause noise induced hearing loss for sufficiently long exposures. As level increases, the safe exposure time decreases. Anything greater than 140 decibels has the potential to cause instantaneous hearing loss even for a single short exposure it's worrisome that around 20% of young adults in the United States have noise induced hearing loss. But for those ages 50 to 59, not only do you deal with age related hearing loss, but 25% of you have noise induced hearing loss. Our lives are increasingly noisy and there are impacts Although humans and animals respond to noise in ways that are still being understood, this graphic summarizes the impacts now close to a loud noise source. Permanent hearing loss may occur as noise potentially deafens. A little farther away, our ears may ring, temporarily dulling our ability to hear quiet sounds. Additionally, research shows that noise disrupts, distracts and debilitates. For example, chronic noise exposure causes some birds to exhibit a response similar to post Traumatic stress disorder in humans and in humans there is a direct correlation between sleep disruption from noise and cardiovascular disease. Furthermore, as shown behind me, exposure to a noise can cause or exacerbate a host of health conditions from diabetes to depression and an increase of just 4dB in background levels near airports. Not even a doubling of loudness causes a 7% increase in violent crimes. That noise causes negative impacts has been known for decades. The 1972 Noise Control act stated it is the policy of the United States to promote an environment for all Americans free from noise that jeopardizes their health or welfare. Yet our world is such that in a 2019 New Yorker article questioned whether noise pollution was the next public health crisis. If BYU research is conducted for the benefit of the world, noise related research is timely. Now, our discussion today shouldn't lead to damage or debilitation, but I want to briefly cover disruption and distraction. Noise disrupts communication. As an example, I'm going to play a recording of a recent BYU devotional address to which I've added substantial background noise. At first, you may be able to figure out who is speaking and some of what is being said. However, when I turn off the noise, notice the difference in terms of both intelligibility and the effort required to hear clearly. But I've come to believe that God loves underdogs. He loves come from behind victories. He loves the impossible. Like President Reese, I believe that God loves underdogs. Noise directly causes fatigue or important messages to be missed. In noisy environments, some animals attempt to alter the pitch of their calls to maximize intelligibility. Whether physically or spiritually, the message is the same. It is harder to communicate in the presence of noise. Now I'd like to illustrate a related principle with a bit of audience participation. I'm going to play a recording that repeats a word Or a short phrase over and over. And I want you to pay attention to what word or phrase you hear. I don't want you to miss it. So please listen carefully. Are we ready? Okay. Now turn to your neighbor and tell them what was being said. President, this is now officially active learning. Okay. You may be surprised to learn that you disagree entirely with your neighbor on what was being said. We polled a bunch of people asking them what they heard, and you can see some answers displayed on the screen. Everything from Yoda to downhill to thank goodness, don't kill. What worries me is the kill just below it. So which is the correct answer? The answer is none of the above. Or you could technically argue that the answer is all of the above because what you actually heard is nonsensical noise that has been carefully crafted to mimic human speech. Pareidolia is a psychological phenomenon where people perceive meaningful patterns or images in random stimuli. These phantom words are a form of auditory pareidolia, with noises that distract us as we pursue meaning where none exists. As a counterexample, in the Old Testament, the Lord tells Elijah to stand before him on Mount Horeb. And as the Lord passes by, he teaches Elijah an invaluable lesson about pareidolia. Probably didn't think you'd hear that in the Old Testament. Wind howling, rocks breaking, earthquakes rattling, and fire roaring are all impressive acoustical events, but without intrinsic meaning. Yet Elijah turned away from the noise and its distractions as he learned to recognize an essential, still small voice. Now, I've introduced you to noise and its impacts, and I've given you examples that probably have you wondering if my background is actually audiology, philosophy, or psychology. But actually, that's what I love about acoustics. It's grounded in physics, but it touches our human experience through many disciplines. As I dive into research my students and I have worked on, I hope you'll continue to make connections as to the impacts of all kinds of noise in our lives. He that hath ears to hear, let him hear. My introduction to noise came as an Undergraduate student, as Dr. Scott Sommerfelt introduced me to the physics of active noise reduction. How does this work? Since sound waves consist of pressure oscillations, if I introduce a wave with oscillations opposite of those of the noise source, I can reduce the noise for a listener. But adjusting the cancellation wave to make it quieter for one person actually may make it louder for others. To reduce the noise for everyone, I must bring the second source near the first. Let's illustrate this. Here's one loudspeaker to your left here that is playing low frequency noise. This is my disturbing noise source that I'd like to cancel. Let's go ahead and turn it off for a second. Now over here, I have another loudspeaker on a cart. Let's go ahead and turn that cancellation source on. Now to you, it's going to sound like the first source is just the same, that the cancellation source is the same as the first source, but it's actually the opposite signal, the anti noise. And as I turn both sound sources on and my students slowly move the cancellation speaker close to the first, everyone, no matter where you are seated, will hear it get quieter. All right, round of applause for the students. Now, in practice, there's much more that goes into active noise reduction than moving loudspeakers on carts. But noise plus noise equaling quiet will always feel like magic to me. By analogy, it is the things closest to us that most strongly influence the amount of noise we hear. And sometimes it takes just a small adjustment to change our whole environment. Little did I know that this research would set me on a lifelong journey studying and learning about and teaching about noise. Now, some noise, like traffic, tends to produce gradual chronic effects like heart disease. However, impulsive noise sources. Impulsive noise sources can directly impact our hearing because at least 13% of the Marines leave basic training with permanent hearing loss. We made weapons noise measurements at Marine Base Quantico that were used to develop better physics models and guide later research on noise exposure in indoor shooting ranges. But as loud as the M16 is pictured here, it is nothing compared to the seven barrel Gatling gun from the A10 Warthog. For this project, we made weapons measurements and then helped an engineering firm design a new firing range at Hill Air Force Base. Acoustical treatments were actually necessary because when the gun was fired in the old range, the shock wave was so intense that the concrete cracked and newly installed light fixtures fell from the ceiling. I'm pleased to report that after our measurements and modeling and recommended treatments were installed in the new range, no further light fixtures were harmed. The undergraduate student who published our study later earned a PhD and now solves noise and vibration problems for the automotive industry. Well, we wanted to continue to study shockwaves, but without a Gatling gun and a university not allowing me to buy dynamite, a convenient noise source was a balloon filled with acetylene or hydrogen. Party sized balloons for measuring hearing safety in the classroom gave way to large scale experiments at the Bonneville Salt Flats where sound levels were 120 decibels. A mile away, undergraduate students published peer reviewed journal articles praised by army researchers who spent their entire careers studying blast waves. Now, you've been wondering when this guy is going to stop talking and do something with these balloons. So that moment has arrived. There we go. Now, I don't dare repeat our salt flats experiments indoors, but I want to illustrate what a small explosion can sound and feel like using a large party balloon filled with hydrogen and oxygen. When we ignite the balloon, the molecules react to produce light, water, heat and sound. Now, I've invited Carolee Sanders to come down and explode the balloon. And Carolee has been the responsible for coordinating this entire forum, and I'd like her to receive a round of applause. All right. Now, Carolee and I are going to wear hearing protection because we're closer, but the balloon size here has been calibrated to not require hearing protection for audience members. Nevertheless, if you want to plug your ears, you're welcome to. All right, are we ready? 5, 4, 3, 2, 1. Now let's go ahead. Let's go ahead and see that again in slow motion. Now, the sound you heard was something like a shotgun. Over here we have a much, much larger balloon filled with just hydrogen. Let's go ahead and explode this one. 5, 4, 3, 2. I'd actually like to welcome Cosmo as the newest member of our research group. Let's go ahead and see that one again. And thank you, Carolee. All right, so this produced a much larger fireball with considerable heat, but because it happens much more slowly, not much sound. Our shockwave research led to the chance to create for Los Alamos National Laboratory better models for blast waves from C4 detonations, which are just a wee bit bigger than the balloons. What you're about to see is 120 pounds of C4 detonated with our closest microphones within 40ft of the blast. All I can say is prayer works. Because supersonic shrapnel from blast after blast narrowly missed many, many, many thousands of dollars of microphones. Tripods, on the other hand, were not so lucky. But as a result of the unique data set, an undergraduate student published the results of an improved model. Other unusual opportunities for students to study noise have come. Now, you may laugh, but as aircraft interiors get quieter, toilet flushes become an increasingly disruptive part of flying. In flight. These toilets use minimum water by leveraging the reduced air pressure outside the aircraft. And when a toilet valve opens, waste is sucked in along pipes into holding tanks at over 100 miles per hour. Now that's dinner conversation. All right. Motorcycle like sound levels, scare children and make some passengers reluctant to use the lavatory for fear of disturbing others. But because vacuum assisted toilets are also used on trains and cruise ships and in green construction, there's widespread motivation to make them quieter. So this was a fascinating physics challenge. What was the source of the loud noises? How is the noise impacted by, for example, the amount of rinse water? Fast forward through a couple years of research and we developed multiple small and simple solutions like relocating a valve to produce a technology that well takes the throne. This first video shows the sound level in decibels used during a flush cycle without noise control. The second you will hear illustrates the effect of BYU's quiet flush that reduces the toilet's noise levels to the gentle whirr of a vacuum cleaner. This message has been brought to you by Technology Transfer. There we go. There are many noise challenges in aerospace toilets aside fighter aircraft noise, the so called sound of freedom contributes to military personnel hearing loss and can disturb nearby communities. To date, more than 30 BYU students have worked with government and industry researchers to understand how the high speed turbulent jet plume from military aircraft produce in these high stakes high pressure measurement environments. BYU students have performed exceptionally well on little sleep to complete setups and resolve issues. This is my first PhD student who after an exhausting week of data collection, fell asleep 100ft from an F22 afterburner. He now works for the Air Force Research Laboratory. This other student now designs the acoustics for our temples, proof that skills learned in physics are widely transferable. A dominant aspect of military jet noise is known as crackle. The intense jet noise radiation results in dozens of shock waves per second shown by these gray arrows and a popping sound that has been described as similar to loudspeaker static or the crumpling of a plastic water bottle. Well, let's listen. Our research has shown that crackle increases relative loudness and annoyance. But guess what happens if you increase the size of the jet plume and then invert it so that it now fires upwards? You now have an explosive volcanic eruption. The January 2022 eruption of the Hunga Tonga volcano was so violent that the blast wa visible by satellite traveled around the world four times. Amazingly, the eruption was audible in Alaska, not six or 600, but 6,000 miles away. Now, when I heard about this, I thought audibility might be explained by shock waves from a very, very large jet crackle on a slow scale. So I contacted some volcanologists and was invited to contribute to an article being written for a little journal. You may have heard of. It's called science. I analyzed global infrasound recordings and found sure enough, shock like characteristics in the Alaska data that matched what people heard. A low frequency house shaking boom occurring every several seconds for about 30 minutes. Now this meant working until at least 2am for a couple weeks, but it was gratifying to collaborate with 75 other authors from 17 different countries, many of which had never heard of BYU. It's difficult to fully grasp the circumstances and sequence of events that led me to rep the y to an international community of geophysicists and seismologists, but I do not believe them to be random pareidolia. As I've pondered this and other research opportunities, I'm convinced there has been clear, meaningful guidance along the way. When it comes to jet noise when it comes to jet noise, we have military aircraft at one scale and we have volcanoes at the other. But in between them are rockets before you experience the bang from a single hydrogen oxygen balloon. Now imagine the four RS25 engines on NASA's Space Launch System center core burning over 250 balloons, 1500 gallons of fuel every second. Then consider that those four engines only provide 20% of SLS's total thrust. Most of it actually comes from the two side boosters manufactured right here in Utah. That's right. During liftoff, SLS creates tremendous power around 50 gigawatts. Now that's far greater than the 1 gigawatt that's electrical power that's produced by a nuclear power plant or the 1.21 gigawatts required to operate a flux capacitor of a time traveling DeLorean. Even though less than 1% of a rocket's mechanical power is converted into noise, the sound during launch is overwhelming. And as global rocket launches increase near exponentially, the potential for rocket noise to become impactful also grows. This schematic describes different potential rocket noise impacts at the rocket, nearby launch structures, wildlife and communities. BYU has researched all aspects as we have measured over 30 launches from California, Texas, Virginia and Florida. We've placed microphones as close as 10ft and as far as 30 miles and have endured all sorts of challenges, from several day delays to hardware being blasted by rocks during liftoff, to vehicles buried up to their axles in sand. But an important opportunity for student learning and significant visibility for BYU came with NASA's Artemis I launch of NASA's SLS, or Space Launch System, the first step in returning humans to the moon. For sls, we had a small NASA STEM grant to take students to Florida to measure the launch from a local beach. And by small, I mean $10,000. But that small grant and invaluable, persistent NASA contacts opened the door to us taking data throughout Kennedy Space center and as close as a mile away, yielding profound insights into the noise from a rocket more powerful than the Saturn V. Now, I can't transport you to Kennedy, but I want to bring SLS to you today to help you experience the sounds of Artemis I from three miles away from the launch pad. Let's watch and listen. And here we go. Hydrogen burn off igniters initiate. 7, 6, 5, 4 stage engine start. 3, 2, 1. Okay, now you know what it's like to go to a rocket launch because last second delays are typical. Okay, we're going to do that again, but listen this time for a slow increase in sound level as the rocket lifts off. And two sound qualities characteristic of rocket launches. The low frequency rumble that decreases in pitch and the intense crackle that gradually lessens as distance increases and the highest frequencies dissipate in the atmosphere. Five, four stage engine start. Three, two, one. Let's hear it for NASA. I have to say, I love putting these Marriott center speakers to work a few miles away. SLS's maximum a weighted noise levels are like those of a rock concert or chainsaw. But in our first paper, we wanted to find something that sort of matched a rocket's unique sound quality. Something that might snap, crackle or pop. Yes, in a scientific paper, we compared SLS to Rice Krispies and discovered for the sake of unadulterated science, that you would have to be surrounded by 40 million bowls of Rice Krispies to equal the maximum a weighted sound level for from SLS launched three miles away. I admit fully that this rocket serial analysis was totally tongue in cheek, meant to illustrate the futility of comparing rockets to any other sound source. But as is typical, we got some passionate reactions on Reddit. One Redditor decried our comparison as unserious science, and another commented that Americans will do literally anything to avoid using the metric system Serial Controversies aside, the SLS measurements have resulted in several student authored papers and other connections and opportunities. In addition to sls, we've now measured the noise from the largest rocket ever built, Starship. Super heavy. Starship is unique because its operation involves catching the rocket's first stage booster in October 2024. We found out only a few days before Starship's fifth test flight that they planned to catch the booster for the first time in less than 48 hours. We had packed a van with equipment and driven nearly 1,600 miles to Boca Chica, Texas. We managed to rapidly set up hardware and measure both the launch noise and the first ever catch of a rocket booster the height of a 20 story building. Just 10 days post launch, we submitted a manuscript to the Journal of the Acoustical Society of America Express Letters. This article has been viewed 14,000 times and received media coverage from the BBC, CNN and others. Kenneth Chang, a New York Times science reporter, actually flew to Texas to shadow us during later measurements and just last week published an article about our research. Now I have to say that being referred to as a sonic detective by the New York Times somehow makes the research feel that much more exciting. During a starship prelaunch livestream, the popular NASA spaceflight media team featured a video of BYU students in the field setting up microphones and interviewed me wearing a BYU acoustic shirt. That video of us representing BYU has been viewed 1.6 million times. Now, flying rocket boosters back to catch towers or landing pads lowers the cost to access space. But one drawback is the sonic boom created as the vehicle approaches the earth at supersonic speeds. When a rocket or aircraft flies faster than the speed of sound, it generates a wake up like a boat. As it pushes the air aside, this forms a shock wave that is heard as a sonic boom. These sonic booms can be quite intense. Now the video I'll play you features an undergrad researcher hearing his first sonic boom five miles away from a Falcon 9 landing zone. My favorite part is the silent high five because they were still recording data. But these intense flyback sonic booms can be heard more than 15 miles away from the launch pad. And as part of projects with Vandenberg Space Force Base in California, we are researching how rocket sonic booms produced during launch and landing operations affect wildlife in communities. This includes placing recorders in locations spread over 500 square miles in Santa Barbara and Ventura counties. Now, we could go out with that bang from the Falcon 9, but instead I want to end with a gentle thump. The startling and potentially damaging nature of sonic booms resulted in a 1973 ban of overland civilian supersonic flight. So for 50 plus years we've been stuck with a flight speed limit that's imposed by the laws of physics. But what if we could reshape the aircraft to smooth out the shock waves so that what is heard on the ground is not a bang bang but rather a thump thump? After decades of research, NASA's X59 aircraft intends to demonstrate this principle of shockwave smoothing. This revolutionary aircraft will soon be flown supersonically over communities to determine acceptability of a thump thump sound predicted to be like distant thunder. Let's listen to the difference between a sonic boom and a sonic thump. It will play twice since 2018, BYU students have helped NASA prepare for X59's flights. We've made sonic boom measurements in the rain and in the desert to help develop improved hardware. For example, we call this large weatherproof windscreen the Compact unit out. Excuse me, the compact outdoor unit. For ground based acoustical recordings, I give you the BYU Cougar, which NASA has now adopted for its design for all the the x59 measurements. Additionally, a graduate student received a NASA fellowship to study how atmospheric turbulence impacts sonic thumps. Just yesterday, she led a student team of setting up 63 microphones in the Mojave Desert to look at variations in sonic boom intensity and got their first data this morning. And because NASA loves a good acronym, her experiment is called the ARRAY Instrumentation for Sonic Thump Observations and Turbulence, or aristotle. So if in coming years we see more low boom, supersonic aircraft and the sonic boom ban lifted, know that BYU students have played a small but meaningful role in this process. In summary, our world is increasingly noisy, whether with explosions, traffic, military aircraft, toilets or rockets. I hope our research contributes to quieting our current cacophony. During the COVID 19 pandemic, our world slowed down and with reduced air, automobile and marine traffic, became a quieter place of it. President Russell M. Nelson said for a time, the pandemic has canceled activities that would normally fill our lives. Soon we may be able to choose to fill that time again with the noise and commotion of the world. Or we can use our time to hear the voice of the Lord whispering His guidance, comfort and peace. Quiet time is sacred time time that will facilitate personal revelation and instill peace. As we find quiet times and sacred groves away from all the noise in the world, it is important that we remember that noise's negative impacts extend far beyond its potential to deafen. Once aware of noise's ability to dull, distract, disrupt and debilitate, we become more intentional about our environment. Like active noise reduction, this intentionality may require us to introduce other sources of sound to counter the noise, like the quiet toilet. Minimizing noise may be built on a series of small, simple measures. And like with NASA's X59 Sonic Thump, it may require some fundamental reshaping. But I am confident that there are meaningful steps we can each take to tune out the crackle and find the calm, all for the benefit of the world. Thank you.
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You've been listening to the recent Speeches podcast presented by BYU Speeches. Please check out our other podcasts, including classic speeches taken from our vast audio library, as well as other BYU Speeches compilations on love and overcoming adversity by study and by faith. Come follow me the Prophet Joseph Smith and Jesus Christ Our Savior and Redeemer. Go to Speeches byu Edu and click on Podcasts for more information. You can also find all BYU Speeches podcasts at your preferred podcast provider.