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. Contains all even and odd harmonics associated with a fundamental tone - making it a rich source for modeling other sounds; Amplitude of each overtone decreases exponentially as a ratio of the harmonic's frequency to that of the fundamental






2. A drive that can read and write on optical media that hold up to 50 GB on two layers; 24- bit/96 kHz for 8-Channel; 24- bit/192 kHz for 6-Channel






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






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






5. AES






6. Smallest interval measurable by a scientific instrument; Defined by bit rate (sample rate x bit depth)






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






8. Splits the input signal and mixes it with an analog copy so that no latency is present






9. 8.75 GB; DS/SL






10. The frequency range that is allowed through a filter






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






12. Method of sampling data at a higher resolution (higher sample rate) as a means of reducing harmonic content during D/A conversion; (x2) oversampling gets rid of all odd harmonic content






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






14. 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






15. Single- pin RCA cable or fiber- optic TOSLINK connector used for digital transfer; 75O coaxial - 2- channel unbalanced; 'Consumer' format of AES3






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






17. The act of a frequency swinging back and forth with a steady - uninterrupted rhythm






18. Measure of the amplitude of a longitudinal wave






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






20. The amount of energy at each wavelength






21. ADPCM; Pulse code modulation that produces a digital signal with a lower bit rate than standard PCM; Records only the difference between samples






22. 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






23. Roughly around 1 -130 ft/s






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






25. Twice as many samples as the highest frequency at minimum; Sampling rate totally controls frequency response






26. 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






27. 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






28. 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






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






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






31. 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






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






33. A sample- by- sample operation on two signals






34. Subtract place values from the decimal number and place ones or zeros in the correct places






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






36. 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






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






38. 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






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






40. 'Reconstructing' part of digital audio






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






42. 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






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






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






45. 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






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






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






48. 16-Bit; 44.1 kHz; PCM; Stereo






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






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