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. 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






2. Inner ear component that attaches to the stapes and helps to decrease the amplitude of vibrations; Causes the masking phenomenon






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






4. 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)






5. MPEG; Standardizing body of audio coding






6. Represents the amplitude component of the digital sampling process; Technique of incrementing a continuous analog event into a discrete set of binary digits (bits)






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






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






9. 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






10. How Loud (Y-Axis) & How Fast (X-Axis)






11. 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






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






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






14. EBU






15. 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






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






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






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






19. The amount of energy at each wavelength






20. When recording you want the smallest buffer available; When mixing you want the largest buffer available






21. 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






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






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






24. Waveform of a pure tone showing simple harmonic motion






25. Difference in brightness between land and pit on a CD Physical Format






26. Eight channel digital surround sound system by Dolby






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






28. 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






29. 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






30. 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






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






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






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






35. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






36. Same as 'aliasing'






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






38. 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






39. 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






40. 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






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






42. 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






43. ADAT Optcal; 8- in/8- out on two cables; Fiber- optic - TOSLINK connector






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






45. 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






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






47. 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)






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






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






50. Father of modern information theory; Solidified the Nyquist Theory by adding the concept that bits per second (binary representation of audio signals) must be at equal intervals to accurately represent data