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The Schroeder reverberator uses parallel comb filters followed by cascaded all-pass filters to produce an impulse response that closely resembles a physical reverberant environment. Learn how to implement the Schroeder reverberator block diagram as a digital filter in LabVIEW, and apply the filter to an audio .wav file.
This module refers to LabVIEW, a software development environment that features a graphical programming language. Please see the LabVIEW QuickStart Guide module for tutorials and documentation that will help you:
•Apply LabVIEW to Audio Signal Processing
•Get started with LabVIEW
•Obtain a fully-functional evaluation edition of LabVIEW

Introduction

Reverberation is a property of concert halls that greatly adds to the enjoyment of a musical performance. The on-stage performer generates sound waves that propagate directly to the listener's ear. However, sound wavesalso bounce off the floor, walls, ceiling, and back wall of the stage, creating myriad copies of the direct sound that are time-delayed and reduced in intensity.

In the prerequisite module Reverberation , you learned how the comb filter structure can efficiently create replicas of a direct-path signal that are time delayed and reduced in intensity. However,the comb filter produces replicas that are time delayed by exactly the same amount, leading to the sensation of a pitched tone superimposed on the signal. Refer back to Reverberation to hear an audio demonstration of this effect. Put another way, the impulse response of the comb filter contains impulses withidentical spacing in time, which is not realistic.

The Schroeder reverberator (see "References" section) uses a combination of comb filters and all-pass filters to produce an impulse response that more nearly resembles the random nature of a physical reverberant environment.

This module introduces you to the Schroeder reverberator and guides you through the implementation process in LabVIEW. As a preview of what can be achieved, watch the screencast video to see and hear a short demonstration of a LabVIEW VI that implements the Schroeder reverberator.The speech clip used in the video is available here: speech.wav (audio courtesy of the Open Speech Repository, www.voiptroubleshooter.com/open_speech ; the sentences are two of the many phonetically balanced Harvard Sentences , an important standard for the speech processing community).

[video] Demonstration of the Schroeder reverberator as implemented in LabVIEW

Structure of the schroeder reverberator

The screencast video presents the structure of the Schroeder reverberator and describes the rationale for its design.

[video] Structure of the Schroeder reverberator and rationale for its design

All-pass filter

The Schroeder reverberator uses all-pass filters to increase the pulse density produced by the parallel comb filters. You perhaps are familiar with the frequency response of an all-pass filter: its magnituderesponse is unity (flat) for all frequencies, and its phase response varies with frequency. For example, the all-pass filter is used to create a variable fractional delay as described in Karplus-Strong Plucked String Algorithm with Improved Pitch Accuracy .

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
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da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
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Application of nanotechnology in medicine
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please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
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Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
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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?
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What is meant by 'nano scale'?
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LITNING
scanning tunneling microscope
Sahil
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Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
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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
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if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
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analytical skills graphene is prepared to kill any type viruses .
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Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
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Bob Reply
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?
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What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
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yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
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why?
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what school?
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biomolecules are e building blocks of every organics and inorganic materials.
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in a comparison of the stages of meiosis to the stage of mitosis, which stages are unique to meiosis and which stages have the same event in botg meiosis and mitosis
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Researchers demonstrated that the hippocampus functions in memory processing by creating lesions in the hippocampi of rats, which resulted in ________.
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The formulation of new memories is sometimes called ________, and the process of bringing up old memories is called ________.
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Source:  OpenStax, Musical signal processing with labview -- sound spatialization and reverberation. OpenStax CNX. Nov 07, 2007 Download for free at http://cnx.org/content/col10485/1.1
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