Tutorial 2: What is MP3?/ Audio File Compression

The history behind MP3 format and its technology is brief and has been around for over a decade. A group of inidviduals known as the Moving Pictures Expert Group developed different compression systems for video data such as DVD's, TV broadcasts, and statellite feeds. These compression systems were developed in order to store large quantities of data in smaller spaces. They also developed a compression system for audio files called MPEG audio Layer 3, otherwise known as MP3.

In today's day and age, audio files are compressed to reduce their file sizes. The bigger an audio file is the more room it takes up on a computer's hard drive and the longer it would take the file to be downloaded off of a website. This problem created a gap. To fill this gap, MP3 formatting of audio files was created. The MP3 format reduced an audio file ten to fourteen times that of its original size. Even with this reduction in size, MP3 files still maintain a large portion of the original quality of sound in the audio file.

According to Marshall Brain, and his article " How MP3's Work", "The MP3 format is a compression system for music." What this means is that MP3 format compresses a song/audio file that is normally thrity-two meagbytes all the way down to three megabytes. This is beneficial because it allows audio files to be downloaded more quickly and once dowloaded take up less space on a hard drive. Hard drives can store up to hundreds of different MP3 audio files.

However, a cost comes with the compression of audio files. Using the MP3 format diminishes some of the original sound quality. MP3 versions of auido files do not sound the same as the originals. This is because some of the file has been removed during the compression process. The vast use of MP3's in place of the orginal files has caused music studios to change the way they mix recordings. There is no longer a concentrated focus on creating dynamic sound. It seems that the world has become used to the sound provided by the MP3 format. In conclusion, Marshall Brain explained MP3 format well by stating that, "MP3 is nothing magical. It is simnply a format that compresses a file into a smaller size so that it's easier to move around and store on your home computer or your portable music player."

Sources: http://en.wikipedia.org/wiki/MP3
              http://computer.howstuffworks.com/mp31.htm#
              http://www.nzhypnosis.com/hypnosis-mp3.html
              http://www.karbosguide.com/hardware/module7d4.htm

"Excel Project"

The excel project was both difficult and time consuming. First I had to manipulate and format a set of raw data. This portion of the project was the easiest. I used the video examples as my guide and was able to manipulate the data set to fit the requirements. Patience was the key for this part of the project. It was hard not to rush through this section and bypass a portion of the directions. However, through trial and error I was able to complete this piece of the project and feel some sense of accomplishment. This was the largest set of data that I have ever worked with in Excel and I had to overcome a few obstacles especially when using formulas. Overall I feel I did well on this part of the project but my difficulties were about to increase.

The second part of the Excel project was the data analysis section. This was the portion of the project where I had to create two pivot tables. The first pivot table was fairly basic. However, I struggled when trying to figure out what to put in the values section of the pivot table. After a few hours of trial and error I realized that the count of the target achieved was the necessary input in the values section. Hopefully it turned out fine. The second pivot table was a nightmare for me. This pivot table I was asked to determine the average percent increase in heart rates for the subjects but the subjects needed to be grouped by decades. I was never able to figure out how to group the subjects by decades. I watched the pivot table videos online multiple times and I read the excel discussion board. Still I was not able to figure out how to group the subjects. I hope I will not be penalized too many points. As far as the other components of the pivot table, I feel I was able to figure them out.

In conclusion, the data analysis portion of this project was extremely challenging. I wasn't able to figure out how to group the subjects by decade and thus ended up not meeting the requirements for my second pivot table. Overall this project tested my patience, my computer skills, and my attention to detail. There were times where I felt like giving up especially with the pivot tables. Luckily the discussion posts and videos were able to help me in creating my first one but I was never able to grasp the concept of grouping. However, I did learn how to manipulate cells by using different addressing techniques. I also figured out how to alter portions of the pivot tables by switching up the inputs into the columns, rows, and values sections. Below is a screen capture of my second pivot table. All 49 subjects are visible because I was never able to figure out how to group them by decade.