Physics P105: Basic Physics of Sound

PhysicsP105: Basic Physics of SoundSpring 2015Homework Assignment #11(Due 11:59 p.m., Monday, April 20)Make sure you show your work online where relevant for full points.1.(2 pts) Loudness compensation artificially __________ high and low frequencies to improve howmusic at low intensity levels sounds.2.(1 pt) Analog sound is __________ in both time and in amplitude.3.(2 pts) Digitized sound allows a huge range between loudest and softest sound that can be recorded,resulting in a very large ________ _________ (two words).4.(2 pts) A .wav file is an example of a ___________ digital format, while a MP3 file is an example ofa __________ digital format where not all of the original sound information is present.5.(1 pt) The ________ sampling theorem states that at least R samples per second are needed toadequately represent a signal containing frequencies up to R/2 Hz.6.(2 pts) You are recording speech from a phone line where the maximum frequency of the speech is8 kHz. What is the miminum sampling frequency you should use to maintain good fidelity andprevent aliasing?7.(2 pts) A ________________ (hyphenated word) converter converts an analog amplitude to a digitalbinary number.8.(2 pts) A CD player uses a ________ _________ (two words) to sense the digitized sound signalrecorded as pits on the surface of the disc.9.(6 pts) Suppose a 18-bit digital representation of an analog signal with amplitude of 10 V (i.e., signalcan vary from +10V to –10 V) is to be used. N =18 bits would allow for a huge dynamic range ofamplitudes, from the smallest number of ________ to the largest number of(2N–1 = _________), for a dynamic range of __________ dB. This corresponds to an amplituderesolution (step-size) of (20 V)/(2N –1) = _________ V.10.(4 pts) The value in binary representation of the following decimal numbers is: 12 =_________ ,22 = _________ , 65 = _________, and 127 = __________ ..11.(4 pts) The decimal value of each of the following binary numbers is: 0110 =_________ ,00101101 = __________ , 10000001 =__________ , and 1111111111111111 = _________ .12.(3 pts) For not-so-accurate reproduction of audio signals up to 20 kHz, a CD stores 44,100 samplesper second for each of the two stereo tracks, with each sample represented by a 14-bit binary "word"(instead of the 16 bits for good fidelity). The number of bits per second that must be read by the CDplayer = ___________ bits/s. If the CD has a playing time of 67 minutes, this corresponds to atotal of _________ bits being stored on the disc.