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. Have odd numbered harmonics






2. 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






3. Anytime bit depth is reduced the gap gets bigger so more dithering is required






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






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






6. Digital and analog processing capability is combined on a single microchip allowing for 1- bit resolution at high sample rates






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






8. The set of rules that computers use to move files from one computer to another on an internet






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. 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.






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






12. 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






13. 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






14. 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






15. Same as 'aliasing'






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






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






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






19. Defines the number of sample per second taken from a continuous signal to make a discrete signal; Governs the frequency response of digital audio






20. 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






21. 15.9 GB; DS/DL






22. 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






23. 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






24. AAC (Advanced Audio Coding); MP3; RA; WMA; OGG Vorbis; Dolby Digital/AC-3; DTS; ADPCM






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






26. 12cm plastic disc; 1.2mm thick; One- sided; Red Laser; 1.6 microns between tracks; 125 nanometer pits






27. Ultra low- latency - 512- channel (on a gigabit network) - less flexible AoE format; Routed like audio cables...not network cables






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






29. Decibels Full Scale






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






31. 8.75 GB; DS/SL






32. 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






33. MPEG; Standardizing body of audio coding






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






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






36. 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






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






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






39. 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






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






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






42. Unit of measurement that is equal to one millionth of a meter






43. 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






44. 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






45. Uses entropy coding as the basis; Computer data compression algorithm that packages files such as .ZIP & .RAR






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






47. A digital filter's time domain output sequence when the input is a single sample is input






48. 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






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






50. 4.38 GB; SS/SL