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Examples of the correction system and the code used to implement it.

These are the files we used to implement our Pitch Correction&Detection system, along with some examples of our results.

Matlab code

When using these programs, type help<name>into MATLAB to determine the format of the inputs and outputs. Vectors are always columns, and sounds are always monaural. Sounds should also be normalized. In general, vectors of pitches refer to windows, and the pitches themselves are in Hertz. Advisory: choose window size of 4000 samples and jump size of 1000, assuming a 44.1 KHz sample.

Pitch detection

Detect using the time-domain Autocorrelation algorithm (findautomin is required):



Detect using the frequency-domain HPS algorithm:


Determine the pitch to which the program should correct:

Pitch determination


Pitch correction

Correct pitch using the Time Shifting algorithm:


Correct pitch using the PSOLA time domain algorithm:


Correct pitch using the Modified Phase Vocoder:



These examples were all generated using the FAST-Auto pitch detector with threshold around 0.05, a 4000 point window, and a 1000 point jump size, using the PSOLA correction algorithm.

Flat correction

Below, listen to how the flat note is corrected. The singer starts out holding a tune, but soon dips below that tone. The corrector helps to pick him up and keep him on the right note.

Original Corrected


Below, listen to how the corrector parses a continuously increasing tone into distinct notes. The singer increased in tone across his entire range, and this was fed into the system. The output sounds as if the singer sang distinct notes.

Original Corrected

Song adjustment

The examples below are derived from a portion of a song: Original

Here, listen to how the corrector operates on this song. The singer was not out of tune to begin with, but there were points at which he deviated from a perfect note and the corrector adjusted his pitch. Corrected

In this last example, we use the correction system in the wrong direction: for distortion! We took the original clip above and attempted to make the singer monotone by demanding the same key for the entire clip. Listen to the results: Adjusted

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Ece 301 projects fall 2003. OpenStax CNX. Jan 22, 2004 Download for free at http://cnx.org/content/col10223/1.5
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