# 0.2 Localization cues

 Page 1 / 1
Learn about two localization cues called interaural intensity difference (IID) and interaural timing difference (ITD), and learn how to create a LabVIEW implementation that places a virtual sound source in a stereo sound field.
 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

Our enjoyment of synthesized or recorded sound is greatly enhanced when we perceive the actual locations of the various musicians on stage. In a high quality stereo recording of a jazz trio, for example, you can tell thatthe drummer is perhaps located slightly to the left of center, the saxophonist is on stage right and the bass player is on stage left. If you have ever flipped on the "mono" (monaural) switch on your stereo amplifier, then you knowthat the resulting sound is comparatively unpleasant, especially when wearing headphones.

We live in a three-dimensional soundfield, and our ears continually experience slightly different versions of any given sound. These variations allow us to place (or localize ) the sound source, even when we cannot see it.

In this module, learn about two localization cues called interaural intensity difference and interaural timing difference , abbreviated IID and ITD , respectively. Each cue relies on presenting a slightly different version of a sound to each ear.

## Interaural intensity difference (iid)

The interaural intensity difference (IID) localization cue relies on the fact that an off-center source produces a higher intensity sound in one ear compared to the other. This technique is also called intensity panning , and is most effective when the listener is wearing headphones. When a multi-speaker arrangement is used in a room,a given sound propagates to both ears. Lower frequencies have longer acoustic wavelengths and are therefore less directional than higher frequency sounds. Consequently, the IID effect works better at higher frequencies above1400 Hz (Dodge and Jerse, 1997).

The screencast video continues the discussion by deriving the equations needed to implement the IID effect using a two-speaker arrangement.

## Interaural timing difference (iid)

The interaural timing difference (ITD) localization cue relies on the fact that sound waves from an off-center source arrives at one ear slightly after the other ear. We can perceive this slight difference in time down to about 20 microseconds(Dodge and Jerse, 1997), and this difference helps us to place the sound source either to the left or right. The ITD cue works best in the lower frequency range of 270 to 500 Hz (Dodge and Jerse, 1997).

The screencast video continues the discussion by deriving the equation needed to implement the ITD effect using a two-speaker arrangement.

## Project: implement the iid and itd localization cues in labview

You can easily experiment with both the IID and ITD localization cues in LabVIEW. The cues are probably easier to perceive when you choose a speech signal for your source.

The ITD cue requires a delay or time shift between the two stereo channels. The delay line can be constructed as a digital filter with the transfer function shown in :

$H\left(z\right)=\frac{{z}^{-N}}{1}$

Stated as a difference equation, the filter is $y\left(n\right)=x\left(n-N\right)$ , which states that the output is the same as the input but delayed by N samples. The forward (or "b") coefficients are therefore zero for all but ${b}_{N}=1$ , and the reverse (or "a") coefficients are zero for all but ${a}_{0}=1$ .

The screencast video provides LabVIEW coding tips to implement the equations and to generate a stereo audio signal.

## References

• Dodge, C., and T.A. Jerse, "Computer Music: Synthesis, Composition, and Performance," 2nd ed., Schirmer Books, 1997, ISBN 0-02-864682-7

where we get a research paper on Nano chemistry....?
what are the products of Nano chemistry?
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
learn
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
revolt
da
Application of nanotechnology in medicine
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
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
Got questions? Join the online conversation and get instant answers!