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. 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






2. 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






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






4. 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






5. 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






6. Twice as many samples as the highest frequency at minimum; Sampling rate totally controls frequency response






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






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






9. Sample Rate x Bit Depth x # of Channels






10. Built into DAWs; Bits are added when signals are mixed together to avoid clipping






11. Inner ear component that attaches to the stapes and helps to decrease the amplitude of vibrations; Causes the masking phenomenon






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






13. 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






14. Lossless Format; Can hold up to 25GB on a single- layer disc and 50GB on a dual- layer disc






15. Apple Lossless; Windows Media Lossless; DTS HD Master Audio; Dolby True HD; FLAC






16. Data reduction technique that does not effect quality of original audio; No effect on original quality; Typically around 50% reduction; Exact reconstruction of digital code for the audio signal






17. Defines the number of sample per second taken from a continuous signal to make a discrete signal; Governs the frequency response of digital audio






18. 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






19. 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






20. Measures the highest levels of a signal being recorded or mixed; Monitors for clipping - which occurs at 0dBFS); Does not always reflect perceived volume of signal






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






22. 15.9 GB; DS/DL






23. Same as 'aliasing'






24. Describes acceptable data - performances both offered and essential for a disc player - and the complete user experience






25. The set of rules that computers use to move files from one computer to another on an internet






26. Based on psychoacoustics - these are the basis of frequency analysis for a perceptual codec;






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






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






29. 12.33 GB; DS/ML






30. The more bits allocated during quantization - the more accurate the measurement






31. Root Mean Square; Refers to taking the square root of all instantaneous amplitudes; Takes the average of those squares; (-6 Peak Level is approximately equal to -20 RMS)






32. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form); There must be a minimum of 2 samples for each cycle in a waveform






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






34. The mathematics - algorithms - and the techniques used to manipulate signals after they have been converted to digital form






35. Snippets of time in which frequency analysis takes place in a perceptual codec






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






37. 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






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






39. Measure of the amplitude of a longitudinal wave






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






41. The number of compressions or rarefactions in one second; The higher the frequency the more compressions & rarefactions per second; Measured in Hertz






42. Unit of measurement that is equal to one billionth of a meter






43. Signal voltage is relayed to a register from sample- and - hold circuit; Holds reference frequencies in binary form that decrease in value; Finds approximated value & assigns binary number accordingly






44. The amount of energy at each wavelength






45. 7.95 GB; SS/DL






46. Governs the frequency response of a digital system; The highest- frequency component that can be captured with a sampling rate; always 1/2 of sampling rate; Also called the limiting frequency






47. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






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






49. If a signal is sampled at a rate higher than twice the highest significant signal frequency and at evenly spaced intervals - then the samples contain all the information of the original signal






50. Uses entropy coding as the basis; Computer data compression algorithm that packages files such as .ZIP & .RAR