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






2. 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






3. 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






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






5. 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






6. 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






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






8. 7.95 GB; SS/DL






9. Accuracy with which an electronic system reproduces the sound or image of its input signal






10. 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






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






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






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






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






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






16. Reduces A/D sample rate from the oversampled rate to nominal rate by turning series of one- bit samples into a series of multi- bit PCM samples; (ex. => 2.8MHz sample rate converted to 44.1kHz and simultaneously converts 1-Bit samples to multi- bit);






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






18. 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)






19. Sample Rate x Bit Depth x # of Channels






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






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






22. 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






23. The amount of energy at each wavelength






24. 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






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






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






27. 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






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






29. Increases or decreases the digital signal so that the loudest sample is brought up to 0dBfs; Uses all bits from dynamic range and makes it even from track to track






30. 12.33 GB; DS/ML






31. 16-Bit; 44.1 kHz; PCM; Stereo






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






33. Method of representing an acoustic quantity with a series of binary numbers; Can have only specific individually distinct values






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






35. Measure of sound pressure over the frequency spectrum - for which a listener perceives a constant loudness when presented with pure steady tones






36. 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






37. 15.9 GB; DS/DL






38. 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






39. Signal conversions are mixed with playback tracks resulting in near-zero latency






40. Number of bits per second processed when sampling sound; (Sampling Rate x Bit Depth) = Resolution






41. 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






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






43. 'Capturing' part of digital audio; Never captures a signal perfectly






44. 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






45. EBU






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






47. AES






48. 'Reconstructing' part of digital audio






49. The frequency range that is allowed through a filter






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