442014 Engineering and Technology Publishing
Echolocation with Sensors on Via Its
Development in Mexico
Rafael Navarrete Escalera1, M. F. Rocha
1, A. Alma Huerta
1, M. Rosario Osnaya1
, M. I. Rocha G2, and E.
Andrade3
1ESIME, Instituto Politécnico Nacional, U.P. A.L. Mateos, G. A. Madero, México D.F. 07738, México.
2Grupo de Fenómenos Ondulatorios, Departamento de Ingeniería Electrónica, Universidad Politécnica de Valencia,
España. 3Instituto de Física, Universidad Nacional Autónoma de México.
Email: [email protected], [email protected], [email protected] [email protected]
Abstract—Currently humans have a skill that most people
have not developed that would use unconsciously called
echolocation. It is crucial for independent mobility of blind
and involves using self-produced sounds and reflections to
locate and recognize objects that are not. Two new
paradigms have enriched the study of this remarkable
ability: the coupling of sensorimotor and sensory
substitution. The first holds that perceptual and motor
systems are coupled processes that require a unified
treatment unavoidable. The second considers it possible to
see with your ears or skin under brain plasticity. The
subject is present in the context of embodied cognition
theory and recent advances in neuroscience are developed
further studies in the third period. This review will reflect
paradigm shifts in the behavioral sciences and the scientific
value of increased human echolocation. The operation
resembles echolocation of active sonar, the animal emits a
sound that bounces when an obstruction and analyzes the
received echo. Achieves well, knowing the distance to the
object (or objects), by measuring the time delay between the
signal issued and you have received. This type of research
was also a method used in military research in World War
two.
Index Terms—echolocation, sensory substitution, distance,
location, sensorimotor
I. INTRODUCTION
Echolocation a solution to the visual limitations
applied in Mexico, has a number of benefits that are
applied technologies to link the sound, acoustics,
engineering, the same echolocation and especially
technological innovations.
It is shown that through the human ear has been able to
do that recognize brain waves through echoes locating
things in different places. This applied physics studies on
the behavior of the waves, the echo and especially
relevant calculations for this, besides the sound
knowledge in all areas.
The development of the human ear and allows us to
distinguish both the qualities of sound (timbre, tone and
volume) as your address, that is, the position in space of
Manuscript received January 13, 2014; revised September 8, 2014.
the source. Not all sounds are perceived by the human ear,
because it can only detect frequencies between 20 Hz and
20,000 Hz. The sounds with frequencies higher than the
human ear to detect the ultrasonic called can be captured
by some animals (dogs, dolphins or bats). In the same
way, sounds extremely serious, below 20 Hz, are not
captured by the human ear, but by other animals, such as
whales.
The ear is divided into three parts: outer, middle and
inner. Outer ear: consists of the pinna (ear), ear canal and
eardrum. Sound waves are collected by the flag that leads
through the ear canal to the eardrum. Middle ear cavity is
bounded by the drum on the one hand, and the base of the
cochlea on the other. Inside are three small bones, called
the hammer, anvil and stirrup. The hammer head bears
against the eardrum and vibrations transmitted through
the anvil to the stirrup. In turn the latter rests on one of
the two membranes which close the cochlea, the oval
window.
Figure 1. Parts of the ear
Inner ear is a hermetic cavity whose interior is flooded
by fluid called lymph. It consists of three elements: the
semicircular canals, the vestibule and cochlea. The
semicircular canals are not directly related to the hearing
have to do with balance. The vibrations of the oval
window of the hall are transformed into the cochlea. The
signals from the cochlea are coded and transformed into
electrochemical impulses that spread via the auditory
nerve to the brain Fig. 1.
What we call sound is a "disturbance" propagating in
the material (gas, liquid and solid) and our sense of
doi: 10.12720/jolst.2.1.44-47
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452014 Engineering and Technology Publishing
hearing can perceive. Therefore not propagate in a
vacuum. The "gap" is the realm of "silence". However, it
can be used as a vehicle there through to electromagnetic
waves (of very different nature) and thus achieve their
diffusion [1].
II. METHODOLOGY
A. Sound Power Level
Is a parameter that measures the way it is perceived
acoustic power (volume).
People do not perceive a linear change (increase /
decrease) in power as they approach / away from the
source. The perception of power is a feeling that is
proportional to the logarithm of that power. This
logarithmic relationship is the sound power level:
1
w
0
WL 10*log
W (1)
W1 = the power to study,
W0 = is the hearing threshold power, which expressed
in SI units, equivalent to 10-12 watts or 1 pW, which is
taken as fixed reference.
As is normally used its submultiple, the decibel (dB),
so to get the result directly would have to multiply the
second term of the formula for 10.
To add sounds not correct to add the values of the
power levels or pressure: they join powers or pressures
that cause them. Thus, two sound sources give 21 dB 42
dB but not 24 dB.
In this case the formula is used:
1 2
10 1010 10 10
X X
presL log dB
(2)
This is the same:
1 210 log log10 10
pres
X XL log anti anti dB
(3)
where:
Lpress= the resultant pressure level
X1 = values of pressure levels to add, expressed in
decibels.
These formulas become levels in their physical
expressions (power or pressure and, after adding) these,
again find coupled expression level [2].
Echolocation and are considered active touch closed
loop behavior, alluding to the system control or closed
loop feedback, which has a relationship established
between the output and the reference input, comparing
and using as a control difference, to reduce the error and
make the output of the system to a suitable value.
In this type of perceptual behavior, subject to control
modulates action perception, the reverse of what happens
in open loop behavior (the output does not affect the
control action), which is the perception that controls
action [3].
This is how the individual looks and build rules given
constant coupling between the action performed and the
subsequent changes that occurs in their feelings.
In echolocation, the action is represented by the
individual exploratory activity performed through self-
generated sounds and movements of head and / or stick
(ie, changes the emission pattern signal and echolocation
/ or motions to optimize capture of the relevant
information).
He feeling is regarding certain tonal percepts and/or
space related to the presence and characteristics of
objects, the person learns (implicitly) as likely to perceive
auditory gestalts [4], [5]
Stoffregen and Pittenger (1995) [6] in an innovative
study analyzed the echolocation from the perspective of
ecological psychology. They noted that virtually no
systematic research on the use of self-generated sounds,
how closely to support and guide action perception, or
what is the parameter that contains relevant information.
They considered that echolocation, the energy of the
stimulus generated by the subject (direct signal) is spread
in the environment and is structured by him to reflect on
environmental objects before returning to the receiver
(reflected signal).
The relevant information is in the relationships
between the patterns of energy output and energy patterns
returning. They argued, as mentioned, that echolocation
and haptic perception are activities in which the action
controls perception (feedback system or closed loop),
exactly the opposite of what happens in other perceptual
behaviors in which the perception guide action (open
loop system).
They argued that certain known physical variables and
other higher order unknown in traditional literature may
underlie this ability. They concluded that this is a skill
used regularly by humans in everyday situations, without
being aware of it. They made a call to the scientific
community to replicate the research in this field using
ecological paradigms of action - perception.
Carlson-Smith and Wiener (1996) [7] devised a battery
of audiometric tests to predict performance efficient
human echolocation. They worked with subjects with
normal vision occluded and found that there was a
positive correlation between particular auditory
measurements, such as the perception of small changes in
intensity and frequency, and performance in echolocation.
In contrast showed no correlation between the
performance and sensitivity for high frequency hearing.
The authors concluded with a number of useful
recommendations for parents and teachers of Orientation
and Mobility.
Rosenblum, and Jarquin Gordon (2000) [8] conducted
one of the first experiments on human echolocation from
an ecological perspective. Based on evidence from
studies on visual perception and previous research on
human echolocation in stationary and dynamic situation,
implemented an action-based model to analyze whether
the participant's movement facilitated the task of judging
distance via echolocation.
Two experiments in an open (15 m by 40 m) relatively
quiet, with few reflective surfaces nearby, using active
locomotion task. Participants with normal vision
occluded repeatedly emitting sounds of your choice (most
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used vocalizations and clicks with his mouth) should
ecolocar wall panel (90 cm x 180 cm) from a stationary
position or while walking towards it.
The experimenter removed the panel after the
participant could locate via echolocation and then asked
to walk to where they had been positioned judged. The
results showed that participants were able to distinguish
quite accurately the distance that was the wall panel that
had received via echolocation.
The tests were somewhat more accurate motion than
the stationary for some distance. The authors discussed
their results in terms of the potential acoustic information
available, both in the static and the dynamic.
B. Mechanisms of Echolocation
The person born or have a severe disability is
immersed in a painful life issues and complex. Visual
impairment-by deep connotations and consequences-is
one of the most disabling and psychologically destructive,
effects that are evident in the area of mobility of the
visually impaired person [9].
There are a variety of "electronic aids" for the blind
person can cope more easily in their daily lives. However,
none has managed to replace or offer the benefits to be
gained from comprehensive systematic training of other's
skills.
Empirical research supported by scientists has shown
that humans have the ability to create mental images of
the environment without using the eyes. Vision and
hearing are close cousins that can process both energy
reflected waves. Vision processes light waves as they
travel from their source, bounce off surfaces through the
atmosphere and into the eyes.
Similarly, the auditory system processes sound waves
as they travel from their source, bounce off surfaces and
enter the ears. Both systems can extract a lot of
information about the environment by interpreting the
complex patterns of reflected energy they receive. In the
case of sound, these waves of reflected energy are called
"echoes".
As already noted, a paradigm of echolocation sounds
generated by the subject is the direct signal and the
echoes, the reflected signal. That is, the primary sound
source is located in the subject itself and the obstacle that
generates reflection, behaves like secondary sound source.
In the literature, and localization of sound localization
barriers are taken to be synonymous. However, strictly
speaking, the first process is involved only in one phase
of echolocation, that is, when it is discriminated obstacle
position (azimuth and elevation) and its relative distance
(phase position).
III. CONCLUSIONS
New approaches to cognitive and ecological study of
the perception that the individual life skills used in
everyday life. From these recent paradigms is considered
that the main function of the auditory system is to
determine characteristics of the sound source and the
sound in the abstract as traditionally held [10].
This complex process involves locating, recognizing
and identifying the sound source from the sounds she
produces (eg family recognize a listening only to walk in
his footsteps, to identify a helicopter just for the sound it
makes).
The electronic devices are often measured in decibels
volume indicators or other arbitrary scale. The VU meter
display instrument called. His reading is often misleading
for two reasons.
The first reason is obvious: the loudness (and the
sound pressure level) is quantities that depend crucially
on the power source and the distance between the source
and the site (where it gets the ear). The second reason is
that the scale of decibleles arbitrary and has no
correlation. The arbitrary scale of zero indicates the
loudness level (power) and optimal operation for the
device.
ACKNOWLEDGMENT
The authors acknowledge the Instituto Politécnico
Nacional for being their Alma matter and the Escuela
Superior de Ingeniería Mecánica y Eléctrica and IPN-
PIFI for providing their facilities to conduct this work.
REFERENCES
[1] S. J. Perez Ruiz, “The human ear, does it generate sound,” Science
and Development, no. 122, pp. 52-59, May-June 1995.
[2] K. S. D. Clark and K. Wise, “Pressure sensitivity in anisotropically etched thin-diaphragm pressure sensors,”
Transactions on Electron Devices, vol. 26, no. 12, pp. 1887-1896,
December 1979. [3] S. Alcántara, “Semiconductor pressure sensor,” Thesis for the
degree of Master of Science, CINVESTAV, Department of
Electrical Engineering, Section of Bioelectronics, Mexico DF, 1993.
[4] F. Bermejo, C. Gómez, and C. Arias, “Head movements in direct
and reflected sound localization by trained and untrained participants,” Revista Tesis - Universidad Nacional de Córdoba,
2008, pp. 31-43.
[5] G. Neuweiler, “Auditory adaptations for prey capture in echolocating bats,” Physiological Reviews, vol. 70, no. 3, pp. 615-
641, 1990.
[6] T. A. Stoffregen and J. B. Pittenger, “Human echolocation as a basic form of perception and action,” Ecological Psychology, vol.
7, no. 3, pp. 181-216, 1995.
[7] C. Carlson-Smith and W. R. Wiener, “The auditory skills necessary for echolocation: A new explanation,” Journal of Visual
Impairment and Blindness, vol. 90, no. 1, pp. 21-35, 1996.
[8] L. D. Rosemblum, M. S. Gordon, and L. Jarquin, “Echolocating distance by moving and stationary listeners,” Ecological
Psychology, vol. 12, no. 3, pp. 181-206, 2000.
[9] Neural Mechanisms of Echolocation in Bats. [Online]. Available: http://www.neuro.uoregon.edu/wehr/lecturenotes/echolocation%2
0lecture%20notes.pdf
[10] W. Yost, “Auditory image perception and analysis: The basis for hearing,” Hearing Research, vol. 55, pp. 8-18, 1991.
Rafael Navarrete Escalera obtains Degree in Electrical Engineering with specialization in
Instrumentation and Control by ESIME-IPN,
Mexico; He has studied Semester "II-00" of the Master in Mathematics Education Level
by the Center for Research and Advanced Studies. He earned his Master of Arts with a
concentration in Educational Anthropology at
the University of Tepeyac. He is a graduate of the Diploma in Training and Upgrade for the
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472014 Engineering and Technology Publishing
New Model Teacher Education (IPN-ANUIES). Graduate Project Management in Educational Innovation at the Polytechnic University of
Cataluña, Spain. He has attended various courses specific purpose, as
well as education and training in educational areas, technical and administrative. In ESIME-Zacatenco México served as: professor,
researcher and supervisor; Assistant Director of Educational Services
and Social Integration; Deputy Director of Outreach and Academic Support; Academic Head of Automation and Control Engineering;
Deputy Academic Academic Department of Control Engineering and
Automation; Supervisory Control Theory Course I; and the College of Computing technical served as teacher
Journal of Life Sciences and Technologies Vol. 2, No. 1, June 2014