Audio- Pràctica 4

Good morning!

In this new post we are going to learn about different waveforms and how they are listened by us.

Depending on the frequency of the signal, the tone we listen is higher or lower. Human ears are supposed to be able to hear frequencies between 20 Hz and 20 KHz. Human voice is supposed to have a frequency between 33 Hz and 3 KHz. So there's no human being capable of screaming at a non-hearable frequency.

In this practice I want you to generate tones and research about their features:

Task list: Answer in the mail or in a word document. You will only have to send me this document

1.- Generate a sinusoidal 30 Hz - 5 seconds-long wave. Can you hear it? How does it sound?
2.- Generate a sinusoidal 2KHz - 5 seconds-long wave. Can you hear it? Compared to the last, how does it sound?
3.-  Generate a sinusoidal 1Hz - 5 seconds-long wave. Can you hear it?
4.-  Generate a sinusoidal 400KHz - 5 seconds-long wave. Can you hear it? Why?
5.- Try to generate different frequency sinusoidal waves. Which is your frequency-listening limit?
6.- Generate a sinusoidal 1KHz tone. Generate a squared 1KHz tone. Generate noise. Which are their differences?
7.- Generate a DTMF (Dual Tone Multifrequency). What does this remind you?
8.- Look for information in Internet about the DTMF. Llok for the frequencies used in each number in a mobile phone. Can you generate DTMF tones in Audacity related to your mobile phone?

Send the document to my mail or answer directly in it.

If you answer in English you will have the chance of getting an extra point.

Good luck!

Xavi

Audio P-3

Good morning!
I am getting used to post in English and every day I think it's more useful.

In this new practice we are going to work with the tone generation and the frequency of tones. As you should know from last year, frequency stands for the number of cycles that a wave performs in a second. The inverse of frequency, period, stands for the time that a cycle needs to come back to its beginning. Finally, wavelenght stands for the distance between to wave peaks, understanding peaks as the highest point of each wave.

So, in music, for example, we know frequency values (in hertz) of each note:
Do: 261,63 Hz
Re: 293,66 Hz
Mi: 329,63 Hz
Fa: 349,23 Hz
Sol: 392 Hz
La: 440 Hz
Si: 493,88 Hz
Do (octave): 523,25 Hz

In audacity, we can add different tracks and combine them in timelines, as we have seen in last practice. The objective of this second is to build, in tones, the melody of Frère Jacques (the most known French song). You will have to set up the lenght (in seconds) of each tone. For example, for the white notes use 1 second lenght, and for the black ones, use 500 ms (0.5 s)

Let's work!

Xavi

Pràctica 2

Good morning!

In this new post I will be asking you to edit your first song. It is going to be easy, as it will be the -I suppose- first contact with the software we are using. The first thing you have to do is to test your audio card and your headphones. If everything goes OK, you can open Audacity, open atube catcher (other software, probably known by you, that we will use to download songs), download a song (remember, in MP3 format) and edit it.

The objective of this practice is to see if you are able to edit a song and what you are capable of. The final result will be sent to me by e-mail and also saved in your personal folder.

So, what should we do? Task list:

-Test audio.
-Play a little with audacity.
-Download a song.
-Try some effects and editting features (cut, paste, double tracks, compression, amplification, etc)
-Save the final song in MP3.
-Send it by e-mail to me.

Good luck!

Xavi

Inici 3r bloc. Pràctica 1

Hi everybody!

We are at the beginning  of a new block, so we start back again. In this unit, we are going to work in audio. I have asked you to bring headphones so that you can listen to the audio tracks you edit and create. We are going to use Audacity, too. Audacity is a free open license software which allows us to edit (filter, cut, amplify, etc) and mix audio tracks. As it is free, you can download it at home, too. If you have not used it yet, I can tell you that it is very intuitive and easy to use. It is alike to windows movie maker, though it is only focused on audio.

But, what have you got to do? First, you will look for information to create a little PowerPoint about audio formats. Then you will add some information about audio software. Finally you will talk about STREAMING (which allows us to watch or listen to videos and audio online).

Task list:

-Create and edit a PowerPoint including the most known audio formats (MP3, WMA, RM, AAC, and others). Explain the differences between MP3 and MP4

-Add some slides with images and a little more information about software associated to these formats (WMPlayer, Winamp, RMPlayer and others).

-Finally, add a pair of slides about Streaming (what it is, what it is for, how it works…)

When done, you will have to show and explain the PowerPoint to the class. And, I almost forget, you will see more English this term. I will ask you to make the effort of doing something in English. Maybe this PowerPoint (although you finally explain it in Catalan) will be a good chance to begin using it.

Thank you, and have a good term!

Xavi