a true test of superiority through sound perception
Results
Male vs. Female Graphs
Music to Non-Music Graphs
Class (Age) Graphs
Every human ear, despite a person’s gender, is divided into three main parts: the outer, middle, and inner ear. Once again regardless of gender, a person loses his/her hearing either genetically, or by being exposed to a frequency above a certain level (Giancoli 314). Through this experiment, we will prove that gender does not affect a person’s hearing.
When one listens to sounds through headphones, one may think that the sound is coming from inside one’s head (even though it is right outside the head). This illusion is called virtual auditory space, or VAS (Carlile 1). This is why people may have trouble finding the speaker we place somewhere.
There isn’t much data on the study of the accuracy with which listeners can find the position of a speaker; therefore, our experiment is fairly new. There are quite a few factors that come into play when one is locating the source of a frequency. Some of these factors are visual cues, memory, and a listener’s expectations (Kistler 160). In a study by Stevens and Newman (1936), people were put on the roof of a building to locate tone bursts with smooth onsets and offsets. The listeners were to indicate the direction of the source with 15 degrees (Moore: 1977 196). This experiment helped to minimize reflected sounds.
To accurately discover where a sound source is, one needs to be familiarized with the sound and the environment around them. Plenge (1972, 1974) found that we do make comparisons with stimulus patterns we have previously heard in judging the location of a sound source (Moore: 1989 206). In our experiment, we are not going to allow our subjects to become used to the frequency so we can conclude whether males or females are able to locate the speaker quicker and more accurately.
In the choir room, we had a circle drawn on the floor divided into increments of ten degrees, and had a spinning chair in the center of the circle. We used a speaker which we set on another chair 3.63 meters away, and lined up with the 40-degree mark on the circle. We set the “FUNCTION GENERATOR” (a.k.a. the thing that controls the frequency) on the floor as far away from the speaker as possible, so as not to heighten the attention in the direction of the speaker. One of us sat next to the “FUNCTION GENERATOR” to turn the frequency on and record data, while the other spun the person in the chair, timed how long it took the person to locate the direction the sound came from, and measured the degrees he/she was off from the direction of the speaker.
Before each person came into the room, we had a little fun with them and made sure that they were blindfolded and could not see anything. Then we led them into the room and sat them on the chair in the center of the circle. One of us went over to the “FUNCTION GENERATOR” (quietly) and waited until the other had finished spinning the person. Each time we would stop spinning the person and have them face the same direction each time.
Instead of turning the volume knob up on the controller, we just had it set at 800 Hz, at a controlled volume, and had one of the chords unplugged until it was time to turn the speaker on. When the person was done spinning, one of us turned the “FUNCTION GENERATOR” on while the other timed how long it took from when the speaker turned on until the person pointed to where it was. Then we would turn the “FUNCTION GENERATOR” off, record how much time it took for the person being tested to locate the sound source, and record how many degrees the person’s guess was off the forty degree mark (which is where the speaker was).
We conducted five trials per person, and for each we recorded their gender, age, and whether or not they have had any music experience. We only used one frequency the whole time: 800 Hz.
The reason we chose this type of design for our experiment is because the circle on the floor provided accurate angle measurements with which we could place the speaker in a direct line from the center. This way we could accurately measure the distance from the person we were experimenting on (hehehe...) to the speaker.
There are several factors which could have influenced this experiment in a negative way. One is that once the person became disoriented, sometimes there would be a noise outside of the choir room or in the office which would reorient the person. However, this shouldn't have been much of a problem because no person knew where the speaker was (due to putting the blindfold on before we led the person in the choir room). It probably did aid a little, because they had to step over the speaker chord on the way to the chair, so they probably had made an approximation. When a noise occurred, other than what we were doing, we would spin the person in the chair again to be sure they didn’t know which direction they were facing.
Another factor of uncertainty is that some of the people were very familiar with the choir room, while some had hardly ever been in there. This could have been an influence because the people who are familiar with it also know the acoustics of the room better; therefore they are able to pick out where a sound is coming from more precisely.
The fact that we stopped every person in the same place for every trial could have been negative, although we believe it was better than stopping them at random spots. When someone is stopped in the same direction multiple amounts of times, he/she probably starts to realize that the sound is only being heard through one of his/her ears, and he/she is only facing one direction. However, this didn’t appear to be a major problem. Two of the people said that it was peculiar that they could only hear it out of their left ear, but they apparently didn’t realize why because they had been spinning and became disoriented. We also had the reaction from people that they began to doubt themselves because they were only hearing the speaker out of their left ear. We tried stopping people at random places the first day we performed our experiment, but the results were too random. Each person’s results were all over the board. For example, one person’s values were as follows:
1. 20 degrees off
2. 70 degrees off
3. 5 degrees off
4. 10 degrees off
It was too random for us to accurately ascertain anything. The second time, our results were much more uniform. There were still a few discrepancies in our data (for example, one person had 100 degrees in a group with mostly 20 degrees), but for the most part it was much more accurate. To fix both the problem of random and the same stops, we could have stopped the chair at two separate degrees on the circle, but even that may get skewed results.
This is a graph. This is another graph.
Click on me!
Click on me!
Our
hypothesis was that there wouldn’t be any prominent difference in the results
of males and females. Through our
experimentation and data, we have shown our hypothesis to be false. Males were more capable of locating the
speaker than females. 
The average time
to locate the speaker were similar for the two; 
however, the degrees off were
dramatically different. Something we
hadn’t thought of before, and found to be true, is that the people with musical
backgrounds had better results than the people without. This probably occurs because the people with
musical backgrounds have ears that have been better trained to recognize sound
than the people without training. 
As a
result, we formulated a new hypothesis:
those people who have had a musical background of some type are more apt
to locate the speaker more accurately, and in a shorter amount of time. 
We also found that, out of the people with
musical backgrounds, those who were older were more accurate than the younger
ones. If we were to research further
this new hypothesis, we would test several (many more than we did test) people
with musical backgrounds at different ages to see how much age affected those
people.
Dr. Carlile, Simon. “The Auditory Neuroscience Laboratory.”
Dr. Giancoli, Douglas C. Physics: Principles With Applications. Princeton Hall.
Englewood Cliffs, New Jersey 1991.
Kistler, Doris J. and Frederic L. Wightman. Human Psychophysics. Springer-Verlay
New York, Inc. New York, 1993.
Moore, Brian C. Introduction to the Psychology of Hearing. University Park Press.
Baltimore, 1977.
Moore, Brian C. Introduction to the Psychology of Hearing. Academic Press Ltd.
Baltimore, 1989.
Alaina Shea and Brandi Church
January 20, 2000
Per. 8