Independent Research Paper 3


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Independent Research Paper 3

  1. 1. Ayla Reau<br />HL Biology per. 5<br />March 8, 2011<br />The Effect of Music with Different Beats per Minute on the Heartbeat Rate of Humans<br />Introduction:<br />The human heart is a fist-sized muscle located a little to the left of the middle of the chest. Sending blood around the body, the heart provides the body with not only the oxygen and nutrients it needs but also carries away waste. The structure of the heart is much like a pump (or two pumps in one) with the right side of the heart receiving blood from the body and pumping it to the lungs and the left side of the heart receiving blood from the lungs and pumping it out to the body. The heart is made up of four different blood-filled chambers and there are two chambers on each side of the heart, one on the top (the atrium) and one on the bottom (the ventricles). The atria are the chambers that fill with the blood returning to the heart from the body and lungs and the ventricles push out the blood to the body and lungs. The atria and ventricles work together – the atria fill with blood then push it into the ventricles; then the ventricles contract and pump blood out of the heart. While the ventricles are contracting, the atria refill and get ready for the next contraction. The blood relies on four valves inside the heart—the mitral and the tricuspid valve, which allows blood to flow from the atria to the ventricles and the aortic and pulmonary valve, which controls the flow as the blood leaves the heart. These valves all work to keep the blood flowing forward, opening up to let the blood move ahead, then closing to keep the blood from flowing backward. Once the blood leaves the heart it circulates around the body through the bodies many arteries and veins, which together are called blood vessels. Circulation of the blood throughout the body delivers oxygen and nutrients to all the cells in the body. The left side of the heart sends oxygen-rich blood out to the body and the returning deoxygenated carbon dioxide rich blood enters the right side of the heart. <br />A healthy heart makes a lub-dub sound with each beat. This sound comes from the valves shutting on the blood inside the heart. The first sound, the “lub” happens when the mitral and tricuspid valves close. The next sound the “dub” happens when the aortic and pulmonary valves close after the blood has been pushed out of the heart. Most people can feel their heartbeat outside of their heart and this is called a pulse. People can find a pulse by lightly pressing on the skin anywhere there is a large artery running just beneath the skin or using a heartbeat rate monitor. Each beat felt is caused by the contraction of your heart. To find one’s heart rate, the speed at which the heart beats, one counts how many beats per minute can be felt. Furthermore, the average resting heart rate is between 70 and 100 beats per minute. Each time the heart beats it propels blood carrying nutrients, oxygen and toxins to locations throughout the body. Too low a heartbeat can result in these important functions not being able to be met. Too high of a heartbeat can result in wearing out of the heart muscle or the hardening of the walls of the vessels that transport the blood throughout the body. Many different factors can increase or decrease the rate of the heartbeat such as stress, infection, rest, medications, exercise, fear, caffeine, etc. Another such factor is music. For listening to music with a slow or meditative tempo has a relaxing effect on people, slowing breathing and heart rate. On the other hand, listening to faster music with a more upbeat tempo has the opposite effect, speeding up respiration and heart rate. If this is the case then music has potential health benefits such as reducing the effects of stress, lessening the risk of coronary heart disease and more. <br />This investigation aims to measure the effect of music with different beats per minute (BPM) on the heartbeat rate in humans. This investigation will test the hypothesis that music with higher BPM will increase heartbeat rate in humans. Five songs, respectively 140-149, 150-159, 160-169, 170-179, 180-187 BPMs will be used. The test subject will be played the songs at the different BPMs and their initial and experimental heartbeat rate will be taken for each of five trials for each song at five BPMs. At the end of the experiment, the heartbeat rate for each BPM song for the subject will be averaged, calculated for percent change, graphed and a conclusion will be drawn. It is predicted that the songs with the higher BPM will increase heart rate.<br />Design: <br />Research Question<br />What is the effect of music with different beats per minutes on the heartbeat rate in humans? <br />Materials<br />5 Songs (140-149, 150-159, 160-169, 170-179, 180-187 beats per minute)<br />Computer (to play the music)<br />Heartbeat rate monitor / pulse monitor <br />A person<br />Method<br />Set up a chair for the person to sit in, then set up your computer. Make sure to keep all the songs at the same volume when played. Do not move the positions of the chair or the computer. <br />114109536195<br />Picture 2: The heart rate monitor and transmitter.Picture 1: Experimental setup.<br />Have the person sit down in the chair as set up in Picture 1.<br />Ask them to put the transmitter under their shirt and around their chest. <br />Then measure their initial heartbeat rate using the watch and record. <br />Take five trials with a one-minute break between. Then calculate the average.<br />Play the 140-149 BPM song for one minute then immediately record their heartbeat rate. <br />Repeat the above step 4 more times with a one-minute break between each playing of the song and record results.<br />Average the heartbeat rates for the person for the 140 BMP song.<br />Then repeat the above steps for the 140 BMP song test for the rest of the BMP songs: 150, 160, 170 and 180 BPM.<br />Variables<br />Independent Variable: Beats per minute of the five songs. <br />Dependent Variable: Heartbeat rate in humans as measured by a heartbeat rate monitor.Controlled Variables: Not changing the placing and therefore distance between the chair and computer, along with having the same volume for the entire experiment will control the volume of the music. The music will be controlled as only one song is selected for each BPM (one song for 140-149, one song for 150-159 etc.) and each person will be played the same songs. The same heartbeat rate monitor will be used for the duration of the experiment. The testing environment will be kept the same. All the people tested will be around the same age group to control possible medical issues. <br />Data Collection and Processing:<br />Raw Data/Data Collection<br />Table 1: The Pulse Per Minute Trials For All Different Beats Per Minute SongsMusic Trials No Music 140-149 BPM150-159 BPM160-169 BPM170-179 BPM180-189 BPMPulsePerMinute (± 3 beats)758186869198778387899097738286889295758085889396728285879196<br />Caption: Table 1 shows all the pulse/minute trials for all different BPM songs including the control or no music trial. Note that the uncertainty for the pulse per minute data is calculated from the data collected.<br />Calculation for Uncertainty: Look for the biggest difference between trials in the columns<br />Uncertainty = (Greatest Number in Data Column - Smallest Number in Data Column) / 2<br />Uncertainty = (77 – 72) / 2 <br />Uncertainty = 2.5 <br />Sample Calculation for Average<br />Ex. The average pulse per minute for the no music trial <br />Average = (Pulse/minute 1 + Pulse/minute 2 + Pulse/minute 3 + Pulse/minute 4 + Pulse/minute 5) / Total Number of Pulse/minute Trials<br />Average = (75 + 77 + 73 + 75 + 72)<br />Average = 74 beats per minute<br />Qualitative Data<br />The subject of the experiment did not move during the no music trials but as the songs increased in beats per minutes the subject tapped their feet and head bobbed more and at greater speeds. The subject also sang along to some parts of the song when the music was played. <br />Processed Data<br />T-Test Results (for Table 1)<br />No music vs. 140-149 BPM – extremely statistically significant<br />No music vs. 150-159 BPM – extremely statistically significant<br />No music vs. 160-169 BPM – extremely statistically significant<br />No music vs. 170-179 BPM – extremely statistically significant<br />No music vs. 180-189 BPM – extremely statistically significant<br />This means that there is a high chance of a correlation between the two variables. <br />0342900Sample Calculation: T-Test Results for No music vs. 150-159 BPM<br />Table 2: The Pulse Per Minute Averages For All Different Beats Per Minute MusicMusic Trials No Music140-149 BPM150-159 BPM160-169 BPM170-179 BPM180-189 BPMAverage PulsePer Minute(± 3 beats)748286889196<br />Caption: This graph shows the average pulse per minute in the subject for all different beats per minute songs including the no music trial (0). Note that the uncertainty of the data is present in the form of error bars but they are too small to see. Caption: Table 2 shows the average pulse/minute for each BPM level.<br />Table 3: The Percent Changes From No Music to the Different Beats Per Minute Song TrialsFrom No Music to...140-149 BPM150-159 BPM160-169 BPM170-179 BPM180-189 BPMPercent Change (%)1116192330<br />Sample Calculation for Percent Change<br />Ex. The percent change in pulse per minute from no music trial to 140-149 BPM<br />Percent Change in Heartbeat Rate = [(Measured – Theoretical) / Theoretical] x 100<br />Percent Change in Heartbeat Rate = [(82 – 74) / 74] x 100 <br />Percent Change in Heartbeat Rate = 10.81081081%<br />Percent Change in Heartbeat Rate ≈ 11%<br />00<br />Conclusion and Evaluation: <br />Conclusion<br />The beats per minute of a song do have an effect on the heartbeat rate in humans. As seen in Figure 1, the heartbeat rate in all levels of BPM songs differed from the control, no music heartbeat rate. Looking at Figure 1 it can be seen that as the beats per minute of the song increased, the heartbeat rate in the subject also increased. For the heart rate in the subject started at 74 pulses per minute and increased to an amount 96 pulses per minute when listening to the 180 to 189 beats per minute song. Moreover, looking at Figure 2 it can also be seen that the percent change from the average no music heartbeat rate to the beats per minute heartbeat rate increased as the song increased in beats. Using the same example from above, the heartbeat rate increased 30 percent from no music to listening to the 180 to 189 BPM song. So, not only does the heartbeat rate increase with the increasing of beats per minute in a song but the percent change in heartbeat rate does also. <br />This conclusion matched the prediction made before experimentation. As it was hypothesized that listening to music with different BPM could slow or speed up heartbeat rate and that music with higher BPM will increase heartbeat rate in humans. Figure 1 and 2 both support this statement. Moreover, this conclusion is quite accurate as seen by looking at the T-Test taken above. All the data from the different BPM levels were compared to the no music heartbeat rate data and each T-Test stated, “by conventional criteria, this difference is considered to be extremely statistically significant”. This means that the data collected has a probable correlation and the there is a high chance of BPM in music effecting heartbeat rate in humans. The accuracy of the data can also be seen by the small error bars on Figure 1. <br />Overall, this investigation showed that there is a very high probability of BPM in music effecting heartbeat rate in humans, with higher BPMs creating faster pulse rates. Although it should be noted that the theory also includes the lowering of heartbeat rate but this was not evidenced in the lab. So, if this lab was to be repeated, songs with lower beats per minute could be used to see if music can lower heartbeat rate. It should also be noted that during the experiment the subject was not sitting still and further experimentation can be done to see if movement caused this result or if the findings in this lab stay the same.<br />Evaluation/ Improvements <br />Most comparative group data averages were extremely statically significant and the hypothesis being tested was supported; however, there could still weaknesses in the procedure and the data collection present. <br />A major weakness in the investigation would have be the fact that during experimentation the subject moved around. The subject occasionally tapped feet and fingers, bobbed head and sang along to the songs during the experimentation period. This could have seriously impacted the data for movement increases heartbeat rate and logically the faster the beats in the song the more the subject moves and therefore their heartbeat rate increases as well. So, the data collected, with the increasing heartbeat rate, might be due to movement and not the beats per minute in the actual song. To attempt to improve upon this procedural flaw, if the experiment is repeated the subject should be told to keep as still as possible and not sing along to the song. So, that it can be assured that the change in heartbeat rate if any is due to the BPM of the songs used. <br />An additional weakness that could have affected the data collected for the heartbeat rate was that the heartbeat rate monitor and transistor provided did not state an uncertainty on the package or online. Therefore, an uncertainty had to be calculated based on the data taken. This means that the data collected could have an extremely large uncertainty, making the data unreliable or it could have a low uncertainty making it more reliable. To solve this problem, an experiment could be done with an instrument that has a known uncertainty or the company that produced the monitors can be contacted for this information.<br />Another weakness was that only one person was tested. This makes the scope of the experiment very narrow, as these results may only apply to people in this subject’s age group or gender. The subject tested was an 18-year-old female and perhaps different results would be found in a 30-year-old male. So, this could be solved by testing more people with a larger range of age groups from both genders. <br />Another possible version of this experiment could be tried, for as mentioned before, research also claims that music can lower heart rate. So an experiment could be conducted with songs of lower BPM to see if they lower the heart rate in humans. <br />