COMD 5070 Exam 1

1000, 5000, lowest, highest - answer-hearing is more sensitive at some frequencies -lowest thresholds are from _______ to _______ Hz -thresholds are much higher for ______ and for ______ frequency sounds 12, nonlinear, bigger - answer-there are _______ semitones in 1 octave -each semitone is a _________ step- each step upward is _______ than the last (about 5.9%) -no semitones are physically identical in Hz, but they SOUND equal in step size, because our human perception of sound is nonlinear 30, - answer-standard DVD/VHS video uses _______ frames/sec, while ultra high speed film uses _____-________ frames/sec 44,100 Hz, 22,050 Hz - answer-the sample rate for compact discs is _________, this means that the sounds played back from the compact disc can go up to ___________ 500, audible - answer-for very brief sounds (below ________ms), duration affects perception -the longer the sound, the more _______ it is -this is because the ear integrates the energy, meaning: a brief sound at a higher amplitude gives you the same amount of energy as a longer sound at a lower amplitude 6-10 - answer-as a general rule, people agree that a ___-___ dB increase is perceived as twice as loud 8 - answer-if a system has a 3 bit resolution, how many amplitude values does it have? a - answer-We say that science is parsimonious. This means that a. it uses the simplest explanation possible b. it is based on the collection of data c. it makes predictions based on physical laws d. none of the above acoustic power, watts per unit area - answer-________ _________ represents the amount of energy transferred in a given amount of time, measured in watts -intensity is measured in ________ _____ ______ ________. sound radiates outward from the source in a sphere, and as the radius gets bigger, the energy is spread over a much larger sphere acoustics - answer-____________ can help by telling us how the larynx is operating or how articulators are moving; measures speech production through microphone readings aerodynamics - answer-__________ describes the pressures and flows and resistances involved in regulating our breath stream as we speak air compression, air rarefaction - answer-microphone voltage represents sound -large positive voltage: ______ _____ -large negative voltage: _______ ________ all frequencies, equal amplitudes, random phase - answer-what does noise look like on a spectrum? (3) anti-aliasing - answer-_______ _________: filtering before digitizing which prevents aliasing -set filter to nyquist frequency and any frequencies above it are deleted and cannot contaminate the recording i.e. using a low pass filter to prevent the higher frequencies from even reaching the digitized system so that they won't contaminate the lower frequency recording by being represented as an alias b - answer-a spectrum differs from a spectrogram because: a. it is a time domain display b. it does not represent time on its axis b - answer-An electroglottograph reveals details of voicing by a. passing a strong light through the glottis b. passing a current across the vocal folds c. passing a flexible scope through the nasal cavity d. passing air through the nares b - answer-the relationship between perturbation and modulation is: a. they are mutually exclusive b. it is possible for both to occur in the same voice b - answer-When a signal is converted from analog to digital form, the number of 'snapshots' per second is the a. quantization accuracy b. sampling rate c. Nyquist frequency d. digitization coefficient band pass - answer-a _______ _________ filter allows a band of frequencies in the middle through, and holds back both higher and lower frequencies band reject - answer-a _________ ________ filter holds back a band of frequencies in the middle and allows both higher and lower frequencies through brown - answer-________ noise falls of at about 6 dB per octave c - answer-A low pass filter a. removes low frequencies b. has no effect on a speech recording c. blocks high frequencies d. amplifies vowels e. none of the above c - answer-A single vertical line on a line spectrum would represent: a. a vowel sound b. white noise c. a sine wave d. a harmonic series e. a high pass filter c - answer-Loudness is best measured by a. calculating the root mean square of a signal b. using a sound level meter c. having a listener make a perceptual judgment d. averaging the mean peak waveform height c - answer-The best way to avoid aliasing during a digital recording is to use a a. band reject filter b. high pass filter c. low pass filter d. band pass filter complex tone - answer-a _________ ________ involves multiple sine waves together, blended, with the fundamental frequency as the lowest frequency component