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






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






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






4. 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






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






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






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






8. Sony sigma- delta modulation based technology that bypasses the decimation and interpolation steps found in PCM converters






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






10. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






11. 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






12. 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






13. Measure of the amplitude of a longitudinal wave






14. MPEG; Standardizing body of audio coding






15. The loudest point of a Full Scale system






16. 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






17. 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






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






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






20. Sample Rate x Bit Depth x # of Channels






21. 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






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






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






24. 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






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






26. 8.75 GB; DS/SL






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






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






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






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






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






32. The frequency above or below which attenuation begins in a filter circuit






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






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






35. 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






36. 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






37. 'Capturing' part of digital audio; Never captures a signal perfectly






38. Roughly around 1 -130 ft/s






39. 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






40. 4.38 GB; SS/SL






41. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






42. EBU






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






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






45. Reference voltage determined by summing the voltage values of a predetermined number of previous samples; Numbers of 1 in row = waveform peak; Numbers of 0 in row = waveform trough; Basis of Sony's Direct Stream Digital (DSD)






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






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






48. Waveform of a pure tone showing simple harmonic motion






49. Decibels Full Scale






50. Occurs as data is assembled into meaningful bits or information and as left & right channels are separated