XP Practical PC, 3e Chapter 14 1 Recording and Editing Sound

XP Practical PC, 3e Chapter 14 2 Recording and Editing Sound In this Chapter, you will learn: –How sound capability enhances your PC –How your PC records, stores and plays digital sound –How speech synthesis works –What you should know about MIDI –How to add sound clips to presentations and Web pages –How to work with digitized sound –About Sound devices

XP Practical PC, 3e Chapter 14 3 How sound capability enhances your PC Your PC contains a sound card which is used to generate sound through speakers or headphones. PC Sound is used in many ways: –Beeps to alert you to –Sounds to tell you an action cannot be done –Music that can be downloaded from the Web –Listening to on-line college courses –Sound affects for games –Audible screens for visually impaired people

XP Practical PC, 3e Chapter 14 4 How sound capability enhances your PC Computers work with two types of sound: –Digitized sound records real music, sound effects for speech. Digitized sound has been converted into electronic signals that can be stored and manipulated. – Synthesized sound is not recorded, but generated from a machine such as a computer.

XP Practical PC, 3e Chapter 14 5 How a PC records, stores and plays digital sound Digital sound is created using a microphone, sound card and software and saved in formats such as.wav,.au and.voc. Characteristics of sound are amplitude (volume) and frequency (high or low note). Samples of the wave are stored in the sound file. The more samples in a file, the better the sound, but the larger the file – measured in KHz.

XP Practical PC, 3e Chapter 14 6 How a PC records, stores and plays digital sound Sampling a sound wave

XP Practical PC, 3e Chapter 14 7 How speech synthesis works Computers can create sounds called speech synthesis resembling spoken words. Most synthesizers use basic sounds (phonemes) strung together to form words. Synthesizers also work from text-to-speech, “reading” the text. Synthesized speech can also be used in getting messages over your voice mail system.

XP Practical PC, 3e Chapter 14 8 How speech synthesis works Using speech synthesizing software

XP Practical PC, 3e Chapter 14 9 What you should know about MIDI MIDI is musical instrument digital interface and specifies a standard way to store music on computers and other electronic devices. MIDI files contain MIDI messages – akin to a player piano roll. MIDI works with instrumental music, but not vocal. MIDI files require much less storage space than digital files.

XP Practical PC, 3e Chapter What you should know about MIDI MIDI music is created by: –Composing it on the computer –Entering the notes on a musical staff –Assigning the notes to different instruments –Adding harmony –Adding percussion

XP Practical PC, 3e Chapter What you should know about MIDI Using MIDI software You can write music note by note, or play it on a MIDI keyboard You can assign an instrument and MIDI track to each musical part

XP Practical PC, 3e Chapter Adding sound clips to presentations and Web pages A sound clip must first be a digitized sound file or a MIDI file. You can compose one or find sound clip files on the Web or to buy. Presentation software packages have specific sound formats they will accept, but WAVE and MIDI are standard Web formats. Other sound formats may require special plug-ins for Web site visitors to be able to use.

XP Practical PC, 3e Chapter Adding sound clips to presentations and Web pages Adding sound to a Web site using Word

XP Practical PC, 3e Chapter Hardware – Sound devices Most modern PCs contain a sound system with: –speakers and/or headphones. Your speaker quality should match your sound card quality. –a sound card, which is a circuit board on the PCs motherboard. Upgrading the sound card to a higher frequency response (Hz) produces better quality sound. FM synthesis and Wavetable synthesis are two sound card techniques available Wavetable synthesis is newer and produces better sound –a microphone.

XP Practical PC, 3e Chapter Hardware – Sound devices A diagram of a typical sound system

XP Practical PC, 3e Chapter Hardware – Sound devices MIDI instruments can be added to your PC sound system. MIDI instruments electronically synthesis music. The most popular instrument is a MIDI keyboard. These MIDI keyboards approximate piano keyboards.

XP Practical PC, 3e Chapter Hardware – Sound devices A MIDI keyboard

XP Practical PC, 3e Chapter Working with digitized sound Using the Windows Sound Recorder program The sound wave playing or recording Slider shows status Record Stop Play Fast Forward Rewind

XP Practical PC, 3e Chapter What do you think? RIAA vs. Rio 1.When you purchase a music CD, do you believe that you should have the right to convert it into any format (such as cassette tape or MP3) for your own use? 2.Do you believe that Rio and MP3 would be more attractive to music pirates than cassette tape? 3.Do you think that it should be illegal to sell an MP3 device, such as Rio?

XP Practical PC, 3e Chapter Chapter Summary You should now know: –What sound capability your PC has –What digital sound is. –How speech synthesis works –What MIDI is –How to add sound clips to presentations and the Web –How to work with digitized sound –About the basic types of sound devices