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. 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






2. 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)






3. Perceptual coding technique that uses louder sounds of a similar frequency to decide what information is to be saved during data reduction






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






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






6. 8.75 GB; DS/SL






7. Samples are duplicated and the playback sampling rate correspondingly increased; Significantly raises the Nyquist limit to a range well beyond human hearing; Processing 'pushes' the distortion resulting from quantization error into these higher frequ






8. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form); There must be a minimum of 2 samples for each cycle in a waveform






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






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






11. Snippets of time in which frequency analysis takes place in a perceptual codec






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






13. 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






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






15. 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






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






17. 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






18. 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






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






20. 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






21. Only 2 digits used; The value of each place (ones - hundreds - etc.) are as follows from greatest to least: 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1






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. Very selective method of lowering buffer levels by halting different levels of audio processing






24. French mathematician that noted that any complex sound can be broken down into a series of component pure tones






25. Accuracy with which an electronic system reproduces the sound or image of its input signal






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






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






28. 8- in/8- out on one cable; 25- pin D- sub connector






29. Decibels Full Scale






30. Series of dots and dashes representing the letters of the alphabet; Most common letters are represented by the shortest dots and dashes; Example of entropy coding






31. Reduces the percieved distortion due to quantization error; Low level white noise source is introduced to make the profile of the quantization 'noise' more irregular; Useful when reducing the number of bits per word in a signal (i.e. when converting






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






33. Branch of psychology concerned with the subjective perception of sound






34. 7.95 GB; SS/DL






35. Sample Rate x Bit Depth x # of Channels






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






37. Cable used to transmit data; Inner cable is surrounded by a plastic insulator - which is surrounded by a wire mesh conductor that insulates the internal signal wire from external interference and an outer casing that functions as a ground






38. 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






39. 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






40. A situation where a calculated value cannot fit into the number of digits reserved for it






41. Algorithm uses matrix of a mid/side microphone pair to determine a side signal & that signal is reduced then distributed as code in stereo






42. 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






43. Very quiet digital amplifier that produces a series of output pulses with the audio signal coded the same as the width of the output pulses; Pulses are used to represent wave forms and are either on or off; Intense signals have long pulses with short






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






45. 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






46. 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






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






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






49. 'Reconstructing' part of digital audio






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