Activity 3.1 - Sound graphs

• Introducing and interpreting sound graphs (sound amplitude versus time)
• Understand that sound graphs can be used for speech recognition

• A computer to play MP3 file and files: mama_papa.mp3.

Or

• A computer with microphone, sound card and Sound analysis program. 
  For example Audacity is a free, open source, sound recorder and editor program.
  Free to download at http://audacity.sourceforge.net/download/.

In this activity students are introduced to speech analysis. They analyse simple sound graphs and try to recognise the sound waveforms of certain syllables and words. The students’ tasks are given in Worksheet: Sound graphs. Let students perform these tasks. If possible let them work in groups. The given mp3 files can be played on the computer, if possible in the Audacity program.
Once students have completed their tasks discuss with them what speech analysis is, how it can be used, what possibilities and difficulties of speech analysis are, etc.
This activity should arise students’ interest in speech analysis.

• Do you know what speech analysis is?
• Do you see any examples or applications of it?
• What do you think of the present and future level of technology in this field?
• Can you think of societal use and abuse of this technology?
• Would you as a judge admit evidence based on speech analysis in court?
• Could voice recognition be abused?
• Can you come up with commercial applications in the field of advertisement and security?