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. Digital Word -> Series of Resistors (each with assigned charges) -> Sample- and-Hold Circuit -> Anti-Imaging Filter (Smoothing Filter) -> Reconstructed Sample






2. EDL; Final list of samples used in the audio editing process; Identified by time code






3. Eliminates frequencies above the Nyquist limit from becoming samples; Occurs prior to quantization






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






5. Single- pin RCA cable or fiber- optic TOSLINK connector used for digital transfer; 75O coaxial - 2- channel unbalanced; 'Consumer' format of AES3






6. Channels are processed one at a time and the results are stored on multiple CPU buffers that alternately send data as DAW requests the data for playback; First few seconds are relayed to the buffer prior to processing and playback and it continuously






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






8. 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






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






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






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






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






13. The ability of a digital system to perform complex DSP without running into problems with overflow or loss of resolution






14. Waveform of a pure tone showing simple harmonic motion






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






16. (AES/EBU); 110O - 2- channel balanced digital audio cable with an XLR connection; NOT a mic cable!!






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






18. 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






19. Sample Rate x Bit Depth x # of Channels






20. Low Pressure; Part in a longitudinal wave where the particles are spread apart






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






22. 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






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






24. Also known as equal loudness curves; Graph that indicates the average ear sensitivity to different frequencies at different SPL levels (as volume increases - these curves flatten out)






25. 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






26. 8- in/8- out on one cable; 25- pin D- sub connector






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






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






29. 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






30. EBU






31. Measure of the amplitude of a longitudinal wave






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






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






34. Playback; I/O Connections; CPU (Streaming); Conversion from DAW or Software






35. 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);






36. Circuit that seizes voltage values with each tick of an A/D device's internal clock






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






38. 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






39. (Time Based) Frequency: Aliasing; Anti-Aliasing Filter; Sample Rate; Nyquist Limit






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






41. Eight channel digital surround sound system by Dolby






42. Mixing data and control characters in a single operation






43. Improper (false) sampling of high frequencies that cause much lower frequencies to be produced when the audio is reconstructed; Foldover happens at higher frequencies as harmonics reach levels that exceed the Nyquist limit.






44. Decibels Full Scale






45. 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






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






47. Have odd numbered harmonics






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






49. VBR; Most common & best data reduction technique; Codecs that encode data by determining how dense or sparse areas of the audio are; Can result in buffering issues






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