Test your basic knowledge |

Digital Audio

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Method used in digital recording and reproduction in which a signal is sampled at various points and the resulting value is translated into binary numbers






2. Pertaining to hearing or sound; Combination of the intensity of air pressure molecules with amplitude






3. As sample rate is increased more room is created for a smoother slope of the attenuation band because Nyquist limit extends well beyond range of hearing with each increase






4. Deviation from a normal - steady pulse or tick of a clock that contributes to misrepresentation of a signal; Result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one dev






5. Process that begins with a fast FFT analysis of the spectra of two input signals - then the multiplication of like frequencies - and IFFT to finalize the process






6. ABR; Codecs that encode data by determining how dense or sparse areas of the audio are while also keeping bit rate within specified limits to avoid rebuffering






7. ADPCM; Pulse code modulation that produces a digital signal with a lower bit rate than standard PCM; Records only the difference between samples






8. Very quiet digital amplifier that produces a series of output pulses with the audio signal coded the same as the width of the output pulses; Pulses are used to represent wave forms and are either on or off; Intense signals have long pulses with short






9. A frequency specified for a filter (digital or electronic) the marks the point at which the frequency content of a signal is altered +/- 3dB






10. A time regulator that makes all samples and bits to align when working with interconnected digital devices; Basically a signal that all of the digital devices refer to when operating.






11. MPEG; Standardizing body of audio coding






12. Have odd numbered harmonics






13. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






14. The process of reducing the space required to store data by efficiently encoding the content.






15. Eight channel digital surround sound system by Dolby






16. The difference between the analog value and the approximated digital value due to the 'rounding' that occurs while converting the analog signal to digital






17. Accuracy with which an electronic system reproduces the sound or image of its input signal






18. 8.75 GB; DS/SL






19. Ratio of magnitude of the analytical signal to the magnitude of the background noise signal






20. Describes various optical disc characteristics including the size and shape of the disc - the size of pits - the speed at which the disc spins - and a multitude of aspects regarding the specifications of the player itself






21. Cable used to transmit data; Inner cable is surrounded by a plastic insulator - which is surrounded by a wire mesh conductor that insulates the internal signal wire from external interference and an outer casing that functions as a ground






22. The loudest point of a Full Scale system






23. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






24. The frequency range that is allowed through a filter






25. Six channel (five speakers and one subwoofer for bass) digital surround sound system by Dolby






26. A situation where a calculated value cannot fit into the number of digits reserved for it






27. Electromagnetic receptor that detects the radiation known as visible light






28. Process of building a complex tone by starting with the fundamental frequency and adding pure tone harmonics






29. Visual graph that shows how loud a sound is at different frequencies






30. ADAT Optcal; 8- in/8- out on two cables; Fiber- optic - TOSLINK connector






31. Data is transmitted over fiber optic lines; Uses a TOSLINK connecter instead of an RCA type; Can transmit multi- channel audio; Not susceptible to ground hum and loops; Able to support far higher rates of data transfer over greater distances than coa






32. A network communications protocol that specifies how machines will exchange data; Uses a broadcast system in which one machine transmits its message on the communication medium and the other machines listen for messages directed to them






33. Branch of psychology concerned with the subjective perception of sound






34. 1.) Bit Rate x Sample Rate (you'll get b/sec) 2.) Multiply by 60 if converting seconds to minutes 3.) Divide by 8 to convert bits to Bytes and get B/min 4.) Divide by 1 -024 to get KB/min and keep doing it until you get desired bit rate specification






35. Digital (binary) measurements of how long each pulse is either on or off; Width of increasing voltage or decreasing voltage is assigned a 1 or 0 respectively






36. High Pressure - Part of a longitudinal wave where the particles of the medium are close together






37. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






38. Based on Full Scale (dB/FS); -6dB represents a loss of one bit so account for this when calculating






39. High channel count; 64 channels on one cable; Coaxial cable with BNC connector or fiber optic with ST1 connector






40. Roughly around 1 -130 ft/s






41. Decibels Full Scale






42. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






43. Waveform of a pure tone showing simple harmonic motion






44. CobraNet; EtherSound; Dante; AVB (currently under development)






45. In order to play multiple channels at one time data is buffered as read to disk; Latency happens between play command & beginning of playback






46. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






47. Level above which audible sounds are painful (125 - 130 db)






48. Sony and Philips optical disc format; Utilizes sigma delta DSD to offer higher resolution; 1- bit; 2.8224 MHz; 6-Channel






49. Very selective method of lowering buffer levels by halting different levels of audio processing






50. Unit of measurement that is equal to one millionth of a meter