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. Psychoacoustic model of data reduction used for general audio compression that aims to transmit only features perceptible to the human ear; Useful for mastering streaming media






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






3. 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);






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






5. Found that aliasing was always a problem no matter how fast you sample; Less data recorded but more accurate; 2 samples per wave length.






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






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






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






9. 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






10. 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






11. 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






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






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






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






15. CobraNet; EtherSound; Dante; AVB (currently under development)






16. 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






17. 12.33 GB; DS/ML






18. Stores only one copy of a stereo signal and assigns it to both channels in order to save 50% of original bandwidth






19. Joint-Stereo Technique; Since the human brain is unable to localize sounds at high frequencies well sounds above 9 kHz threshold are encoded in mono






20. Mixing data and control characters in a single operation






21. 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






22. 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)






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






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






25. 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






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






27. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






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






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






30. Deviation from a normal - steady pulse or tick of a clock that contributes to misrepresentation of a signal; Result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one dev






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






32. 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






33. 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






34. Data transmission protocol over which computer network traffic travels; Poorly suited to real- time transmission but numerous attempts have been made to harness the technology because of its flexible routing; Uses simple Cat5 cabling; Resists interfe






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






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






37. Serial Copy Management System; main difference between AES3 & S/PIDF






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






39. Electromagnetic receptor that detects the radiation known as visible light






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






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






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






43. Circuit that interprets the meaning of the symbols as they were chosen and arranged by the encode






44. 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






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






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






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






48. 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






49. 7.95 GB; SS/DL






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