# 0.13 Lab 9a - speech processing (part 1)  (Page 3/5)

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## 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

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

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:

${X}_{m}\left({e}^{j\omega }\right)=\sum _{n=-\infty }^{\infty }x\left(n\right)w\left(n-m\right){e}^{-j\omega n}$

Here, $x\left(n\right)$ is our speech signal, and $w\left(n\right)$ is a window of length $L$ . Notice that if we fix $m$ , the stDTFT is simply the DTFT of $x\left(n\right)$ multiplied by a shifted window. Therefore, ${X}_{m}\left({e}^{j\omega }\right)$ is a collection of DTFTs of windowed segments of $x\left(n\right)$ .

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 $w\left(n\right)$ .

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

what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
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