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






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






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






4. 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






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






6. 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






7. Mixing data and control characters in a single operation






8. Softest sound that can be heard by the average human ear (0 dB)






9. 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






10. 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






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






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






14. More accuracy in low amplitudes and less in higher amplitudes






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






16. Eight channel digital surround sound system by Dolby






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






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






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






20. The process of reducing the space required to store data by efficiently encoding the content.






21. Measure of the amplitude of a longitudinal wave






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






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






24. 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






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






26. 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






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






28. 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






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






30. The difference in volume between the loudest and quietest sounds of a source






31. Visual graph that shows how loud a sound is at different frequencies






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






33. 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.






34. 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






35. 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)






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






37. 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






38. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






39. 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






40. 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






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






42. 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






43. 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






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






45. Toshiba developed digital audio interface utilizes fiber optics as a transmission medium.






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






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






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






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






50. Discrete incremental distinctions made between the value of one sample and the next; Breaks down bit depth into a series of evenly spaced intervals