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. 8- in/8- out on one cable; 25- pin D- sub connector






2. 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






3. 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






4. The elapsed time it takes for a packet of data to arrive at its destination; Lagging or pause of an audio signal as digital processing occurs; Can be managed utilizing several forms of 'audio monitoring'






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






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






7. A method of representing real numbers using a mantissa and an exponent






8. Industry Standards: -6 dB Peak = -20 RMS Meter






9. Allowance of noise floor below that which is required for the final product






10. AES






11. Father of modern information theory; Solidified the Nyquist Theory by adding the concept that bits per second (binary representation of audio signals) must be at equal intervals to accurately represent data






12. Represents the amplitude component of the digital sampling process; Technique of incrementing a continuous analog event into a discrete set of binary digits (bits)






13. The difference in volume between the loudest and quietest sounds of a source






14. Reduces A/D sample rate from the oversampled rate to nominal rate by turning series of one- bit samples into a series of multi- bit PCM samples; (ex. => 2.8MHz sample rate converted to 44.1kHz and simultaneously converts 1-Bit samples to multi- bit);






15. A sample- by- sample operation on two signals






16. 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






17. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals






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






19. 7.95 GB; SS/DL






20. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






21. 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






22. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






23. CBR; Codecs encodes data at a constant rate regardless of density of the audio file






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






25. HD Audio format; Lossless Compression; 24- bit/96 kHz; 5.1 Surround or 24- bit / 192 kHz stereo sound






26. Amplitude meter that takes the square root of all instantaneous amplitudes and averages them to find a mean and squares that value; Useful with particularly complex waveforms






27. Softest sound that can be heard by the average human ear (0 dB)






28. Method of sampling data at a higher resolution (higher sample rate) as a means of reducing harmonic content during D/A conversion; (x2) oversampling gets rid of all odd harmonic content






29. Multi-Bit Words; (Pulse Code Modulation)






30. Specific set of instructions for carrying out a data reduction technique that determines how to 'save' binary data information efficiently






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. Eight channel digital surround sound system by Dolby






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






34. Data reduction technique that selectively removes original information in order to significantly reduce the file size; Some data is lost; Files can be reduced up to 99% in size (90% with no perceived sound quality loss); Bit rate effects the perceive






35. EBU






36. 1.) Taking a series of evenly- spaced measurements 2.) Signal contains no frequency components higher than half the sample rate






37. Measure of the amplitude of a longitudinal wave






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






39. Method of representing an acoustic quantity with a series of binary numbers; Can have only specific individually distinct values






40. Sum of all harmonics; Sum of sine and cosine waves which have frequencies f - 2f - 3f - 4f...






41. Reduces the percieved distortion due to quantization error; Low level white noise source is introduced to make the profile of the quantization 'noise' more irregular; Useful when reducing the number of bits per word in a signal (i.e. when converting






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






43. Contains all even and odd harmonics associated with a fundamental tone - making it a rich source for modeling other sounds; Amplitude of each overtone decreases exponentially as a ratio of the harmonic's frequency to that of the fundamental






44. Rate at which energy is drawn from a source that produces a flow of electricity in a circuit; Expressed in volts






45. Algorithm uses matrix of a mid/side microphone pair to determine a side signal & that signal is reduced then distributed as code in stereo






46. 4.38 GB; SS/SL






47. Number of bits used to represent the smallest unit of information in an audio file; Greater bit depth = better quality audio






48. Full Scale; Type of metering that measures level in digital recording system; Recording and Mixing levels should NEVER exceed 0dB FS in digital audio or clipping will occur






49. 'Reconstructing' part of digital audio






50. Each bit in the bit depth is equal to a _____ increase in dynamic range