Digital Signal Processing

Digital Signal Processing

This post is about storing sound waves in a digital way.

To convert an analogue sound wave into a digital one is must pass through a digital signal processing system, this puts the sound through a filter to remove unwanted frequencies and then it is converted from analogue to digital. You can then process the signal as you wish using certain operations such as filters etc. To then listen to the sound it must be passed through a converter changing it back to analogue then another filter which brings it back to an analogue sound for the human ear.

There are some advantages and some down sides to converting an analogue signal to a digital one.

This link will take you to a page giving you a list of all the pros and cons http://www.planetoftunes.com/digiaudio/pros_cons.html

I will first explain one of the downsides to the conversion which is the sample rate.

Converting to digital is a complex process as a sound wave is a flowing curve but to get the signal in a digital way you have to choose a sample rate, which means for every time it takes a sample it will take the point it is at in the curve. after collecting all the points it will use them to make a line that resembles a curve

This means that the signal will lose detail unless you increase the sample rate but the more you increase the sample rate the larger the size of the digital file.

In this image example the top file would be much larger in size than the one at the bottom.

Yet one advantage to digital signals is they are extremely easy to alter. As the signal basically becomes a line of code meaning you can change almost everything about the file with a program such as the pitch. This would be a lot harder to do on an analogue signal.