<< Chapter < Page Chapter >> Page >

Inlab report

  1. Give your estimate of the pitch period for the voiced segment, and your prediction of the gender of the speaker.
  2. For each of the two vectors, VoicedSig and UnvoicedSig , list the average energy and number of zero-crossings.Which segment has a greater average energy? Which segment has a greater zero-crossing rate?
  3. Hand in your zero_cross function.

Phonemes

Phonemes in American English. See [link] for more details.

American English can be described in terms of a set of about 42 distinct sounds called phonemes , illustrated in [link] . They can be classified in many ways according to their distinguishingproperties. Vowels are formed by exciting a fixed vocal tract with quasi-periodic pulses of air. Fricatives are produced by forcing air through a constriction (usually towards the mouth end of thevocal tract), causing turbulent air flow. Fricatives may be voiced or unvoiced. Plosive sounds are created by making a complete closure, typically at the frontal vocal tract, building up pressure behind the closureand abruptly releasing it. A diphthong is a gliding monosyllabic sound that starts at or near the articulatory position forone vowel, and moves toward the position of another. It can be a very insightful exercise to recite the phonemes shown in [link] , and make a note of the movements you are making to create them.

It is worth noting at this point that classifying speech sounds as voiced/unvoiced is not equivalent to thevowel/consonant distinction. Vowels and consonants are letters , whereas voiced and unvoiced refer to types of speech sounds . There are several consonants, /m/ and /n/ for example, which when spoken areactually voiced sounds.

Short-time frequency analysis

As we have seen from previous sections, the properties of speech signals are continuously changing, but may be considered to be stationarywithin an appropriate time frame. If analysis is performed on a “segment-by-segment” basis, useful information about the constructionof an utterance may be obtained. The average energy and zero-crossing rate, as previously discussed, are examples of short-time featureextraction in the time-domain. In this section, we will learn how to obtain short-time frequency information from generally non-stationarysignals.

Stdtft

Download the file go.au for the following section.

A useful tool for analyzing the spectral characteristics of a non-stationary signal is the short-time discrete-time Fourier Transform , or stDTFT , which we will define by the following:

X m ( e j ω ) = n = - x ( n ) w ( n - m ) e - j ω n

Here, x ( n ) is our speech signal, and w ( n ) is a window of length L . Notice that if we fix m , the stDTFT is simply the DTFT of x ( n ) multiplied by a shifted window. Therefore, X m ( e j ω ) is a collection of DTFTs of windowed segments of x ( n ) .

As we examined in the Digital Filter Design lab, windowing in the time domain causes an undesirable ringing in the frequency domain. This effectcan be reduced by using some form of a raised cosine for the window w ( n ) .

Write a function X = DFTwin(x,L,m,N) that will compute the DFT of a windowed length L segment of the vector x .

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Purdue digital signal processing labs (ece 438). OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col10593/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Purdue digital signal processing labs (ece 438)' conversation and receive update notifications?

Ask