Author Archives: pharata

Group 3 Results and Conclusion


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Explanation of Results:

The results in the above graph show the average dB levels for each condition. The line across the center of the graph shows the mean dB level of all trials, 66.59 dB. The standard deviation from this mean is 16.439 dB.

The vast majority of the conditions we tested do not pose a threat to our hearing. Sound during lectures, during meals, from computer speakers, in our rooms, and in the library was not found to be harmful. Even while working in the Vassar Infant Toddler Center,  surrounded by crying babies, there seems to be very little danger. However, some of the sounds recorded were loud enough to eventually cause hearing damage. According to the National Institute on Deafness and Other Communication Disorders and to The American Speech-Language-Hearing Association, repeated or prolonged exposure to sounds at or above 85 dB can cause damage to, or death of hair cells. Hair cells are sensory receptors of the auditory system, in the cochlea. Damage to hair cells often results in hearing loss.

The average amplitude of the Villard room party we measured was 93.8 dB. According to the Center for Disease Control and Prevention (CDC), repeated exposure to this amplitude for under two hours could be dangerous to hearing. The sound intensity reached as high as 101.5 dB in the Villard room party. According to the CDC, repeated exposure of just 15 minutes at a time can cause damage when the amplitude of the sound is at 100 dB. This is to say that going to Villard room parties repeatedly over your time at Vassar, could cause permanent hearing loss.

We tested the intensity of sound that comes out of headphones and earbuds multiple times in the project. When listening to music at 100% volume from a headset, the mean amplitude was only 60.86 dB, which does not pose any threat to hearing, even after long exposure. Listening to music at 100% volume from Apple earbuds, the mean amplitude was 83.39 dB and the intensity went up to 91.48 dB at some points. Over years, these intensities can damage ears after repeated exposure of just a few hours a day. Apple earbuds have holes on the back that let some of the sound escape from them. They are made to lower the likelihood of causing damage to your ears. For one of our runs, keeping the volume constant, we covered these holes and found a mean amplitude of 91.46 dB and a high of 101.9 dB. The mean amplitude of the sound from the covered earbuds was essentially the same as the highest amplitude emitted from the uncovered earbuds. The highest amplitude for the uncovered earbuds run was high enough to cause damage after exposure of less than 15 minutes a day, according to the CDC. We also tested another brand of earbuds, JVC, that do not have holes on the back to release sound. The mean amplitude was 90.66 dB and the highest was 97.23 dB. These values were higher than the sound levels we measured from untampered Apple earbuds, and only slightly lower than the intensity measured when the Apple earbuds were covered. This indicates that the holes on the back of Apple headphones do in fact work to protect listeners from hearing loss.

Another potentially hazardous source of sound we are exposed to is from musical instruments. We measured the sound emitted from an oboe, and found a mean amplitude of 91.29 dB and a high of 101.40 dB. Over a few years, exposure to these sound levels for even less than 2 hours at a time, can cause permanent damage. This is important to note because people who play instruments often have 2-hour long rehearsals, and have to practice by themselves on top of that.

Somewhat surprising to us, was that the ACDC at dinner time reached sound levels of 91.31 dB. The mean amplitude was only 79.9 dB, which is not damaging, but the sound did get intense enough to cause some damage over extended periods of time. Considering that many Vassar students eat at the ACDC every night for months, this is an interesting find. According to the CDC, repeated exposure to 90 dB for even less than 2 hours at a time can cause hearing damage. The data suggests that the sound fluctuates enough that no student would be exposed to 90 dB of sound for an entire 2 hours at the ACDC. However, it is something to keep in mind on especially busy ACDC nights.


Our results were for the most part as predicted. For example, we did not expect quiet places, such as the library or our own rooms, to be loud enough to cause hearing damage; we wanted to study them for comparison. We expected the sounds at the Villard room party to be intense. However, we did not realize how damaging they would be. As explained above, repeated attendance at these parties could cause permanent hearing loss. We expected the sound emitted from headphones at a high volume to be enough to damage ears, because this is one of the main warnings you are given when told about hearing loss. However, we did not realize the difference that different types of headphones/earbuds would have on our measurements. The same song was played at the same volume through different earbuds, and resulted in different amplitudes.

Problems that arose:

It is important to point out the limitations of our study. We were only able to measure most conditions one time and the data would be stronger if the measurements were repeated. We also had difficulties when measuring the sound emitted from headphones/earbuds. We held the microphone up to the speakers, in an attempt to imitate the placement in relation to our ears when we are actually listening to music. However, in actuality, part of what makes headphones/earbuds so dangerous, is that the sound is tunneled through the ear canal to the inner ear. We were not able to recreate this, and some of the sound escaped during our measurements. This would be an interesting problem to attempt to solve. Possibly a model of the human ear canal would be needed to take accurate measurements of which sounds are really reaching and damaging hair cells.

Take away message:

In order to prevent hearing loss while at Vassar, students can limit their prolonged exposure to Villard room parties and limit their proximity to those practicing loud instruments. Additionally, we have observed the effect of tampering with headphones, and demonstrated the importance of using earbuds as intended, and at moderate volumes. Investing in a pair of headphones that allows sound to escape may be beneficial, as would be keeping them in their original condition.

Science we learned:

Although we already knew about sound amplitude and decibels, through the project we learned the significance of these measured values. We learned that 30-40 dB is very quiet while 85+ dB can be damaging over time. We also learned how to use a Sound Level Meter (SLM), which we used to take our data. By playing with the different SLM settings in order to figure out which to use, we learned more about it. For example, we could either record continuous measurements of fluctuating sound, or just record the maximum values, depending on the setting. We also learned that different settings are needed to measure lower amplitudes versus higher ones. We learned that the SLM has a microphone that senses and records sound. When connected to the LabQuest 2, the data resulting from the recorded sounds was displayed as a graph. We could then connect the LabQuest 2 to a computer with Logger Pro to further analyze the sound.

Additional data we would have liked to look at:

If we could have done this differently, we would have also tried to record the frequencies of the sound waves. With our limited amount of time, we were only able to obtain the amplitudes of the sound waves. We would have also liked to note how often an average person is exposed to these sound levels and for how long. We had some events that were extremely loud that many students only attend once a month, so the effect of these occasions may seem insignificant in the grand scheme of things.

The Next Step:

If we had another six weeks, we would have taken a lot more data. Particularly, we would try to have a larger variety of data, but also enough points for each activity to get a good average for each activity. We would have also liked to calculate how long the exposure to a certain activity had to be to damage our ears.


“About Hearing Loss.” CDC. n.p., n.d. Web. 25 Feb. 2014.

“Noise.” ASHA. n.p., n.d. Web. 17 Feb. 2014.

“Noise-Induced Hearing Loss.” NIDCD. NIH, Oct. 2013. Web. 17 Feb. 2014.


Group 3 Data


Graph of Data

Average dB

Table of data


Data Point Location, date, and time Description Average dB dB Range d(dB)/dt in dB/s Settings Inputter Graph


Jewett. 9:23pm on 2/13/14 Noise level during night time in my dorm (wellness and quiet).


38.00 – 48.86


S/Reset/A/Lo Christopher Graph


Library. 3:15pm on 2/12/14 Studying in library. No conversations.


37.70 – 53.74


S/Reset/A/Lo Christopher Graph


Jewett. 12:40pm on 2/14/14 Noise level during day time in my dorm (wellness and quiet).


41.91 – 48.52


S/Reset/A/Lo Christopher Graph


Raymond. 9:45pm on 2/18/14 Listening to “Arabella” by Arctic Monkeys on computer. Microphone 72.5cm from computer (comfortable ear distance when computer on lap) at 50% volume.




S/Reset/A/Lo Phe Graph


ACDC. 3:30pm on 2/12/14 Closing time for ACDC (big side).




S/Reset/A/Lo Hannah Graph


OLB 205. 12:00pm on 2/17/14 Physics 152 lecture.


43.40 – 67.35


S/Reset/A/Lo Christopher Graph


Jewett. 7:50pm on 2/13/14 Conversation with a friend in my dorm.


42.40 – 80.32


S/Reset/A/Lo Christopher Graph


Raymond. 9:41pm on 2/18/14 Listening to message on iPhone at 100% volume. Microphone against speaker. Message begins at t=5s.




S/Reset/A/Lo Phe Graph


Jewett. 9:13pm on 2/13/14 Listening to Kings&Queens – 30STM, volume at 100%, using headset with volume at 100%, however headset is on my head and microphone is 0cm from left ear.


50.78 – 67.38


S/Reset/A/Lo Christopher Graph


ACDC. 12:00pm on 2/13/14 Noise level at ACDC (big side) during lunch.




S/Reset/A/Lo Phe Graph


Jewett. 8:58pm on 2/13/14 Listening to Kings&Queens – 30STM, volume at 60% and microphone 10cm from speakers.


41.28 – 71.53


S/Reset/A/Lo Christopher Graph


Retreat. 6:00pm on 2/18/14 Noise level at Retreat during dinner.




S/Reset/A/Lo Phe Graph


Vassar’s Infant Toddler Center. 2:30pm on 2/18/14 The infant room at the ITC, with babies crying sporadically




S/Reset/A/Lo Hannah Graph


Jewett. 9:07pm on 2/13/14 Listening to Kings&Queens – 30STM, volume at 100%, using headset with volume at 100%, microphone in place where head should be (2-4cm apart from each ear piece).


42.28 – 81.31


S/Reset/A/Lo Christopher Graph


Retreat. 3:00pm on 2/17/14 Lunchtime at the retreat, crowded




S/Reset/A/Lo Hannah Graph


Retreat. 12:08pm on 2/18/14 Noise level at Retreat during lunch.




S/Reset/A/Lo Phe Graph


ACDC. 6:20pm on 2/12/14 Dinner time on the west side (big side) of ACDC.




S/Reset/A/Lo Hannah Graph


Raymond. 10:40 on 2/17/14 Listening to “What Makes You Beautiful” on iPhone from apple earbuds at 100% volume. Earbuds up against microphone.




S/Reset/A/Hi Phe and Hannah Graph


Raymond. 10:34pm on 2/17/14 Listening to “What Makes You Beautiful” on iPhone from jvc earbuds at 100% volume. Earbuds up against microphone.




S/Reset/A/Hi Phe and Hannah Graph


Jewett. 8:35pm on 2/17/14 One of my friends practicing with her oboe from t=4 to t=113. 109 seconds of data.


77.99 – 101.40


S/Reset/A/Lo Christopher Graph


Raymond. 10:45 on 2/17/14 Listening to “What Makes You Beautiful” on iPhone at 100% volume. Apple earbuds with holes on back covered. Earbuds up against microphone.




S/Reset/A/Hi Phe and Hannah Graph


Villard room. 12am on 2/15/14 Villard room party 100 nights, dubstep-like music was playing. 5-6 feet away from speakers.




S/Reset/A/Hi Hannah Graph

Sample experimental Setup Photo


Experimental Setup Explanation

Level of sound (in decibels) was collected using a Vernier Sound Level Meter (Vernier SLM-BTA)  in conjunction with a Vernier LabQuest 2. The data was collected under 22 different conditions, as specified in the table above. All data, with the exception of data point 20 (see table), was recorded for 180 seconds. The Time Weighting switch on the Sound Level Meter (SLM) was set to “S” (slow), as is standard for most measurements. The Maximum Level Hold switch on the SLM was set to “Reset,” so that the screen would continuously display the sampled reading as opposed to the maximum reading. The Frequency Weighting switch on the SLM was set to “A,” which measures sound levels that most match those in the human hearing range. The Power/Measurement Range Switch on the SLM was most often set to “Lo,” which measures amplitudes in the range of 35-90 dB. When appropriate (when dB exceeded 90), the switch was set to “Hi,” which measures amplitudes in the range of 75-130 dB.

Explanation of Data:

The data is displayed in the table above. After collected, all data was transferred to the computers and analyzed in Logger Pro The mean amplitude (dB), range, and slope of each graph was extracted using Logger Pro. This information, along with a photo of each graph is in the table. The mean amplitudes will be used to determine which conditions are damaging to human hearing after prolonged exposure. According to the National Institute on Deafness and Other Communication Disorders and to The American Speech-Language-Hearing Association, repeated or prolonged exposure to sounds at or above 85 dB can be damaging. Based on this statistic, the data will be analyzed to determine which sounds (based on mean dB) are dangerous.

Technology involved:

  Two Sound level meters: Vernier SLM-BTA (Type 2) were used in conjunction with two Vernier LabQuest 2 to record the sound level of each condition. The Vernier LabQuest 2 recorded the data and provided graphical representation of the data for each of the conditions. For further analysis, the Vernier LabQuest 2 were connected to computers (a MacBook Pro and a Samsung Series 9 Laptop), which had Logger Pro installed. We utilized the stats tool and the linear fit tool to analyze the data in Logger Pro. Further more, we created a graph of the average dB level exposure per activity (Average dB for each data point) and created a chart of all of the data using Google Docs.

Conditions under which data was taken: 

Twenty-two conditions with various amplitude levels, from studying in the library to a Villard room party, were studied. Please see table above for specifics.


“Noise.” ASHA. n.p., n.d. Web. 17 Feb. 2014.

“Noise-Induced Hearing Loss.” NIDCD. NIH, Oct. 2013. Web. 17 Feb. 2014.