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. Full Scale; Type of metering that measures level in digital recording system; Recording and Mixing levels should NEVER exceed 0dB FS in digital audio or clipping will occur






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






3. (Amplitude Based) Amplitude: Voltage; Quantization; Bit Depth; Quantization Intervals; Quantization Noise; [Signal:Quantization Noise Ratio]; Dither; Dynamic Range






4. 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






5. Each bit in the bit depth is equal to a _____ increase in dynamic range






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






7. Measure of the amplitude of a longitudinal wave






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






9. 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






10. Eight channel digital surround sound system by Dolby






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






12. More aggressive lossy data reduction techniques that require further manipulation of the stereo field; Examples are 'Intensity' & 'M-S'






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






14. 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






15. 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






16. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






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






19. 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






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






21. 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






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






23. Signal that uses variable voltage to create continuous waves resulting in an inexact transmission






24. 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






25. The loudest point of a Full Scale system






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






27. 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






28. 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






29. Allowance of noise floor below that which is required for the final product






30. 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






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






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






33. 12.33 GB; DS/ML






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






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






36. 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






37. 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






38. 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






39. Same as 'aliasing'






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






41. 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






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






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






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






45. 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






46. 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






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






48. 15.9 GB; DS/DL






49. 7.95 GB; SS/DL






50. Mixing data and control characters in a single operation