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. 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);






2. 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






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






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






5. 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






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






8. A time regulator that makes all samples and bits to align when working with interconnected digital devices; Basically a signal that all of the digital devices refer to when operating.






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






10. Measuring equipment in A/D conversion that processes voltage and provides a value for that voltage






11. 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






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






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






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






15. 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)






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






17. In order to play multiple channels at one time data is buffered as read to disk; Latency happens between play command & beginning of playback






18. Allows for an internal sample rate at multiples of the input and output rates; Alleviates the need for steep 'brickwall' filters; Often combined with internal '1- bit' processing; Increases smoothing effect






19. Mixing data and control characters in a single operation






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






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. 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






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






24. 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






25. Fractional part of a floating- point number; Also called the mantissa; Defines precision






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






27. 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






28. Digital and analog processing capability is combined on a single microchip allowing for 1- bit resolution at high sample rates






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






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






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






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






33. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






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






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






36. 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






37. Eight channel digital surround sound system by Dolby






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






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. 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






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






42. Leaving space at beginning and ending of song for data crunching during mastering; Last step in mastering process






43. The art of deciding where to place a processor in signal flow based on how that processor will be influenced by the other processors in the path






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






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






46. 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






47. Removes high frequency images and noise and smoothes the stair case output coming from of the sample and hold circuit; Also called a SMOOTHING FILTER






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






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






50. Level above which audible sounds are painful (125 - 130 db)