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. 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






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






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






4. Roughly around 1 -130 ft/s






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






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






7. 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






8. 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






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






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






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






12. The more bits allocated during quantization - the more accurate the measurement






13. 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






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






15. 1st commercially successful AoE format for the transmission of digital audio - video - and control signals over 64- channel 100Mbps Ethernet networks






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






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






18. Multi-Bit Words; (Pulse Code Modulation)






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






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






21. Data reduction technique that does not effect quality of original audio; No effect on original quality; Typically around 50% reduction; Exact reconstruction of digital code for the audio signal






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






23. 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






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






25. 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






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






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






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






29. Six channel (five speakers and one subwoofer for bass) digital surround sound system by Dolby






30. The difference between the analog value and the approximated digital value due to the 'rounding' that occurs while converting the analog signal to digital






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






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






33. 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






34. AES






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






37. 7.95 GB; SS/DL






38. Computer program or device capable of encoding and/or decoding a digital data stream with the end result being a reduced file size






39. EDL; Final list of samples used in the audio editing process; Identified by time code






40. 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






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






42. (AES/EBU); 110O - 2- channel balanced digital audio cable with an XLR connection; NOT a mic cable!!






43. 16-Bit; 44.1 kHz; PCM; Stereo






44. Improper (false) sampling of high frequencies that cause much lower frequencies to be produced when the audio is reconstructed; Foldover happens at higher frequencies as harmonics reach levels that exceed the Nyquist limit.






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






46. Root Mean Square; Refers to taking the square root of all instantaneous amplitudes; Takes the average of those squares; (-6 Peak Level is approximately equal to -20 RMS)






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






48. 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






49. RAM holds in memory audio data before it is transferred to the memory controller; Certain amount of data is processed before large amounts of data are streamed to prevent latency






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