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. Take up half as many bits (50%); Algorithm can keep same quality by lossing the stereo track






2. Splits the input signal and mixes it with an analog copy so that no latency is present






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






4. 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






5. 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






6. 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






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






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






9. Same as 'aliasing'






10. Increases D/A sample rate from nominal rate to oversampling rate by turning series multi- bit PCM samples into 1- bit samples; (ex. => 44.1kHz sample rate converted to 2.8MHz and simultaneously converts multi- bit samples to 1- bit); Low Pass Filter






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






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






13. 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






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






15. Sample Rate x Bit Depth x # of Channels






16. Used when the reference pressure of a sound is 20 microPa (0.00002); Sound Pressure Level; Measure of amplitude






17. The continuous loss of signal strengths as a signal travels through a medium






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






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






20. Number or variable that represents the number of times the base of a power is used as a factor; Defines magnitude






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






22. 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






23. The loudest point of a Full Scale system






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






25. Used as the main disc from which other discs are made; Composed of ground glass with a very fine photoresistor layer; An imaging laser burns pit and land patterns in preparation for duplication






26. 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






27. 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






28. Difference in brightness between land and pit on a CD Physical Format






29. 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






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






31. Most significant lossless coding technique in current use; Measure of disorder in which long strings of data are represented by short symbols and uses the shortest symbols to represent the most common repetitive audio data maximizing data reduction






32. Overtones that contribute to the timbre of a sound and make up a complex waveform's physical characteristics






33. Mixing data and control characters in a single operation






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






35. 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






36. Number of bits per second processed when sampling sound; (Sampling Rate x Bit Depth) = Resolution






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






38. AAC (Advanced Audio Coding); MP3; RA; WMA; OGG Vorbis; Dolby Digital/AC-3; DTS; ADPCM






39. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






40. Having a repeated succession of waves or curves as in a sound waveform






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






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






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






44. 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'






45. AES






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






47. Voltage -> Dither -> Anti-Aliasing (Low Pass Filter) -> Sample & Hold Circuit -> Successive Approximation/Quantizer --) 100111010 (PCM Audio File)






48. Subtract place values from the decimal number and place ones or zeros in the correct places






49. 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






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