Task summaryWhat you will learn:
How to estimate the download time of a file. Understand that a sound file can be represented as a graph. How you will be assessed: |
Key terminologyBandwidth:
A measure of how quickly data can be downloaded or uploaded. It is usally measured in bits per second (bps) or megabits per second (mbps). Waveform: A graphical display of a sound file Hertz: This is a unit of frequency - it is defined as one cycle per second. |
Activities
Measuring bandwidth
In order to stream music over the Internet like existing music streaming services do, we need to understand about bandwidth. This topic was covered earlier, so this should be revision for you.
Generally we refer to storage in bytes (B) and transmission rates in bits (b).
Discussion: Downloading files is not the same as streaming. What do you think are the differences and why would you choose to stream rather than download?
Calculating an estimated download time: sometimes you need to check how long it will take to download a file from the Internet. It is useful to know how to do this. Look at this worksheet and complete the table.
In order to stream music over the Internet like existing music streaming services do, we need to understand about bandwidth. This topic was covered earlier, so this should be revision for you.
Generally we refer to storage in bytes (B) and transmission rates in bits (b).
- A 2MB file is two megabytes in size, whereas a download speed of 2mbps is two megabits (0.25 megabytes) per second.
Discussion: Downloading files is not the same as streaming. What do you think are the differences and why would you choose to stream rather than download?
Calculating an estimated download time: sometimes you need to check how long it will take to download a file from the Internet. It is useful to know how to do this. Look at this worksheet and complete the table.
Digital Sound
Sounds are represented in waveforms. Looking at waveforms can give a valuable clue about the way sounds are stored on a computer system.
Amplitude - Loudness
The higher the amplitude (loudness), the higher the wave form for example.
Sounds are represented in waveforms. Looking at waveforms can give a valuable clue about the way sounds are stored on a computer system.
Amplitude - Loudness
The higher the amplitude (loudness), the higher the wave form for example.
Frequency
A frequency of 1 Hz means one wave cycle per second. A frequency of 10 Hz means ten wave cycles per second, where the cycles are much shorter and closer together.
A frequency of 1 Hz means one wave cycle per second. A frequency of 10 Hz means ten wave cycles per second, where the cycles are much shorter and closer together.