![Graphics and multimedia
applications [ITE2203]
Chapter five (5)
Sound Management
By
Balyejusa gusite (Bsc. IT, Msc. Is)
Augsoft.Systemz@gmail.Com](https://image.slidesharecdn.com/chapterfive-250207102158-9078421f/85/graphics-and-multimedia-applications-Chapter-Five-pptx-1-320.jpg)
graphics and multimedia applications Chapter Five.pptx
- 1. Graphics and multimedia applications [ITE2203] Chapter five (5) Sound Management By Balyejusa gusite (Bsc. IT, Msc. Is) [email protected]
- 2. • Sound is a form of energy that is produced by vibrations traveling through a medium, such as air, water, or solids. These vibrations create waves of pressure that our ears detect and interpret as sound. • Sound can vary in pitch, which is determined by the frequency of the vibrations (how rapidly they occur), and in volume, which is determined by the amplitude of the vibrations (how strong they are). • Sound is essential for communication, music, and many other aspects of our daily lives. • Sounds also can be combined in a multimedia presentation to provide information and enhance the other media being presented. Introduction to Sound
- 3. Types of sound Audible Sound: This is the type of sound that humans can hear, typically ranging from about 20 Hz to 20,000 Hz in frequency. Infrasound: These are sound waves with frequencies below the lower limit of human hearing, typically below 20 Hz. Infrasound is often generated by natural phenomena like earthquakes or by human-made sources such as large machinery. Ultrasound: Ultrasound refers to sound waves with frequencies above the upper limit of human hearing, typically above 20,000 Hz. Ultrasound is used in medical imaging, industrial testing, and various other applications. White Noise: White noise is a type of noise that contains all frequencies at equal intensity. It's often used to mask other sounds, aid in sleep, or for sound therapy purposes.
- 4. Types of sound cont… Musical Sound: These are sounds produced by musical instruments or voices with specific pitch and timbre characteristics. Musical sounds are often organized into melodies, harmonies, and rhythms. Environmental Sounds: These include sounds from the natural environment such as wind, rain, birdsong, as well as human-made sounds like traffic, machinery, and voices. Transient Sounds: Transient sounds are sudden, brief sounds, like a clap of thunder or a door slamming. Periodic Sounds: Periodic sounds have a repeating pattern, like the sound of a clock ticking or a sine wave.
- 5. Why sound in multimedia? 1. Enhances Emotional Impact: Sound can evoke emotions and create atmosphere in multimedia content. 2. Improves Engagement: Well-designed sound can captivate the audience and keep them engaged with the multimedia content. 3. Provides Context and Information: Sound can provide important context and information that complements the visual elements of multimedia. 4. Increases Immersion: Sound can enhance the sense of immersion in multimedia experiences, making viewers feel like they are part of the action. 5. Supports Accessibility: Sound is essential for making multimedia content accessible to all audiences, including those with visual impairments. 6. Reinforces Brand Identity: Sound can play a key role in reinforcing brand identity in multimedia content. 7. Adds Depth and Realism: Sound adds depth and realism to multimedia content, making it feel more lifelike and dynamic. audio effects create a sense of depth and realism that enhances the overall viewing experience.
- 6. Types of waves Longitudinal waves A longitudinal wave is one where all the particles of the medium (such as gas, liquid or solid) vibrate in the same direction as the wave. Sound waves are longitudinal waves. When longitudinal waves travel through any given medium, they also include compressions and rarefactions. Compression occurs when particles move close together creating regions of high pressure. For example, a vibrating tuning fork creates compressions and rarefactions as the tines move back and forth. Transverse waves: A mechanical wave is transverse when all the particles of the medium, which are solid or liquid (and never gas), vibrate perpendicularly at right angles, up and down, and continue to move in the direction of the wave. For example, the ripples on the surface of a lake are transverse waves. Sound does not move through transverse waves except in special conditions.
- 7. Characteristics of sound wave Frequency • This is the number of cycles a sound wave creates in one second. • Cycle is measured from one wave peak to another. • The standard measurement for frequency is called hertz (hz). Amplitude • Amplitude is the volume or loudness a particular sound makes. • The louder the sound, the higher the amplitude will be. • The unit of measure for loudness or volume is decibel (db). The two main characteristic in sound waves are frequency and amplitude.
- 8. Digital sound • Refers to the reproduction and transmission of sound stored in a digital format. • The digitizing and storage of sound or music on a computer or compact disc. • A digital audio signal can be converted to different format and this starts with an analog-to-digital converter(adc) that converts an analog signal to a digital signal. • After being sampled with the adc, the digital signal may then be altered in a process which is called digital signal processing where it may be filtered or have effects applied. • Audio data compression techniques, such as mp3, advanced audio coding or flac, are commonly employed to reduce the file size. • The digital audio signal may then be stored on cd, a digital audio player, a hard drive, a usb flash drive, or any other digital data storage device, may be transmitted e.G. Via internet. • For play back , the last step, digital audio is converted back to an analog signal with a digital-to-analog converter(dac).
- 10. Sound Sampling Process • For a computer to work with audio waves, they must be converted from analog to digital form. • This is done through a process called sampling, in which every fraction of a second a sample of the audio is recorded in digital bits • There are two factors that affect the quality of the digitized audio: Sample rate: how often the analogue signal was sampled in one second. The three most common sample rates are; 11.025 khz, 22.05 khz, and 44.1 khz. Higher sampling rate = larger file size Sample size: sample size is the amount of information stored about the sample. The two most common sample sizes are 8 bit and 16 bit. The greater the sample size, the better the quality of the audio.
- 11. Sound channel • Two types: • Monophonic • Stereophonic Mono or non-stereo sound is the early sound system used a single channel of audio for sound output. Stereophonic sound divides sounds across two channels (recorded on two separate sources) then the recorded sounds are mixed so that some elements are channeled to the left and others to the right. • A stereo recording of the same size and sample rate has twice the file size of a mono recording.
- 12. Audio/Sound File Formats Wav audio (.Wav) - standard audio file format used mainly in windows pcs. Commonly used for storing uncompressed, cd-quality sound files, which means that they can be large in size. Wave files can be encoded to reduce the file size (for example the GSM or mp3). Sound (.Snd) - snd is a file extension for a sound file used with a variety of platforms. Real audio (.Ra, rm) - designed for streaming audio over the internet. Audio file format (.Aif) - the standard audio file format used by apple. Midi (.Mid) - it is a common format for music files across all computing platforms. Mp3 audio (.Mp3) - the mpeg layer-3 format is the most popular format for downloading and storing music. By eliminating portions of the audio file that are essentially inaudible, mp3 files are compressed to roughly one- tenth the size of an equivalent wav file while maintaining good audio quality. We recommend the mp3 format for music storage. Windows media (.Wma) - the popular windows media audio format owned by microsoft.