Glossary CH3

Question 1

Hertz

Answer 1

Frequency unit from the international measuring system that equals the repetition of a phenomenon whose period is a second. It is abbreviated as Hz.

Question 2

Frequency

Answer 2

It is the number of cycles that happen in a second.

Question 3

Echolocation

Answer 3

It is the location of an object through the reflection of sound waves. It is used by some animal species such as bats, and cetaceans, and it may have technological applications such as the sonar system.

Question 4

Infrasound

Answer 4

It is a sound whose vibration frequency is lower than the one which can be perceived by the human ear.

Question 5

Ultrasound

Answer 5

It is the sound whose frequency of vibrations is superior to the highest limit perceived by the human ear. It has many industrial applications and it is also used in medicine.

Question 6

Sound

Answer 6

It is the sensation produced in the hearing organ by the vibrational movement of the bodies that is transmitted through an elastic means.

Question 7

Elasticity

Answer 7

It is the characteristic that a material has to recover its extension and shape when a force that deformed it stops being put on it.

Question 8

Acoustics

Answer 8

It is a branch of physics that studies the sound production, transmission, storing, perception and reproduction.

Question 9

Transducer

Answer 9

It is the equipment that transforms a type of energy into another one and may work as a recipient or as a generator.

Question 10

Tuning Fork

Answer 10

It is a voice and instrument regulator that consists of a Steel sheet folded as a hook with a foot, and when it is hit, it presents 435 vibrations per second.

Question 11

Compression

Answer 11

It is the effort that an object is subject to by the action of two opposing forces that tend to diminish its volume.

Question 12

Rarefaction

Answer 12

It refers to making a gaseous body less dense.

Question 13

Cycle

Answer 13

It is the complete sequence of a periodic vibration. It goes from rarefaction to compression.

Question 14

Period

Answer 14

It is a period of time that happens in a cycle.

Question 15

Sound Wave Frequency

Answer 15

Measured in Hertz (Hz) is the number of cycles that go through a same point during a second. In other words, it is the number of cycles per second.

Question 16

Wavelength

Answer 16

It is the distance that the sound goes over in a complete cycle of change in pressure and it is the physical measure of a cycle’s length.

Question 17

Amplitude

Answer 17

It is the distance between a balance point and the highest wave point.

Question 18

Tone

Answer 18

It is the subjective perception of frequency. There are high tones and low tones. In order to measure them, we use hertz.

Question 19

Decibel (dB)

Answer 19

It is a measuring unit that compares the minimum that human can hear (odB) against the level we want to measure.

Question 20

Absorption

Answer 20

It is the process in which sound is absorbed by an object when crashing against it.

Question 21

Reflection

Answer 21

It is the quantity of acoustic energy that will change directions when it crashes against the edge of an object.

Question 22

Refraction

Answer 22

It is the change in direction of the sound wave due to a variation of the means of scattering.

Question 23

Bitrate

Answer 23

It is the transmission rate. It refers to the number of bits that is transmitted in a unit of time, usually kilobits per second.

Question 24

Codecs

Answer 24

It means order-decoder. It is software that consists on an algorithm to compress and decompress video in real time. Its use doesn’t interfere with the playing speed. There are also codecs for audio files.

Question 25

Wrapper

Answer 25

It is the way of organizing information related to digital audio that is not part of the sound per sec such as headlines, artwork, encoding configurations, etc. A wrapper can use different codecs.

Question 26

WAV

Answer 26

(Wave) Most used format without compression. It belongs to Microsoft/IBM. Format to play non-streaming files.

Question 27

AIFF

Answer 27

(Audio Interchange File Format) Format used in the Apple platform.

**with NO compression**

Question 28

CDA

Answer 28

(Red Book Audio Standard) An industrial standard used to encode the audio of compact (CDs).

Question 29

MP3

Answer 29

(MPG-1, Audio Layer 3) First one to get highest compression without much data loss. One of the must used by webpages. Format for quicker reproduction as streaming where it is not necessary to download the file to a device. It has a patent.

Question 30

ACC

Answer 30

(Advanced Audio Coding) Supported by Apple to be used on their devices. It is the successor of the MP3 because it can handle a larger level of compression without reducing its quality.

Question 31

MIDI

Answer 31

(Musical Instrument Digital Interface) Communciation protocol that allows electronic musical instruments, synthesizers, computers, and other devices to communicate among them. They only contains instructions which requires less storage than the actual sound.

Question 32

Audacity

Answer 32

Free open source digital audio editor and recording computer software application, available for Windows, OS X, Linux and other operating systems.

Question 33

Garage Band

Answer 33

Software application for OS X and iOS that allows users to create music or podcasts.

Question 34

Monaural Sound

Answer 34

(Also called Mono) Given when an audio is stored in one single channel and it lacks spatial sensation.

Question 35

Stereophonic Sound

Answer 35

(Stereo Sound) It is stored in two channels that can be reproduced in different loudspeakers and simulate the sensation of listening on one single side (left or right).

Question 36

Surround Sound 5.1

Answer 36

Stores the information in more channels that are located around us: 3 at the front (left, center, and right), and one more that produces the frequencies from 20 up to 200 Hz

Question 37

Streaming

Answer 37

It is the reproduction of audio and video files with no need to be downloaded to a device. It is played through fragments sent sequentially through a net, usually, the Internet.

Question 38

Surround Sound 7.1

Answer 38

Stores information in 8 different channels. In order to make the surround sound effect, the loudspeakers have to be strategically placed at certain distance and directed towards certain angles. The more loudspeakers are handled, the more complicated their configuration is since each room has absorption, reflection and refraction conditions.