Download Methodical instructions (indication)

"Affirmed"
At methodical session of the chair of medical
and biological physics
2007. The report №
chief of chair
Shaplavskij M.V.
Methodical instructions (indication)
for plan students self- preparation
“Audiometry”
Module 2: Basic regularities of biomechanics and electricity and use of them in
medical diagnostic and treatment
Pithy module 3 Basic laws of biomechanics and use of it in medical diagnostic and
treatment.
Chernivtsi-2007
Objective: To Study find derivative to function and to can her apply attached to decision of
medical-biological tasks.
Introduction:
Derivative functions one of basic notions of higher mathematics. On base of this notion can
be calculated basic flowing descriptions of different medical-biological processes, in particular
flowing speeds of these processes /bacterium reproduction speed, blowing speed about bacterium,
diffusion speed of infectious disease/.
Background:
1. Notion of function.
2. Function. Border and regulations of her finding.
3. Basic elementary functions /sedate, model, logarithmic, trigonometrical functions their basic
properties and graphs.
Basic question:
1. Determination of function and derivative function.
2. Physical and geometrical maintenance derivative.
Practical exercise:
1. To analyze the basic typical tasks on finding derivative and to learn a methods of
their decision.
2. To find derivative functions, which offer by teacher /as attached to decision on
board
so
and
independently
to
clear
up
herewith
the
incomprehensible
questions
and decisions receptions and to clear up them by the medium of teacher.
Final knolege and skills:
Students should know:
1. Governed finding derivative of basic functions.
2. Governed finding of derivative sum, work, particle and complicated function.
Students should be able:
1. To Find derivative functions.
2. To Apply derivative for finding of speed flowing different processes.
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Contents of theme
Of all the mechanical waves that occure in nature, the most important in our everyday lives are
longitudinal waves in a medium, called sound waves.
Type of
Audible
sound
Infrasound
Ultrasound Hypersound
sound
wave
16>20.000
Frequency <16 Hz 20.000
>1013 Hz
Hz
Hz
A human ear is sensitive to waves in case the following four condition are fulfild:
1) a source of sound;
2) a medium elastic between the hear and the source of sound;
3) waves are in the frequency range from about 20 to 20000 Hz (this range is called the audible
range)
4) the intensity of sound waves is sufficient to obtain human sound perception.
1.Objective characteristics of sound
1) frequency (main characteristic of simple tone);
2) acoustic spectrum;
3) intensity of sound a wave;
4) pressure of sound
2.Classification of sound
1) tones
2) noise
3)Acoustic shock
3. Dynamic Range of Hearing
4. Subjective characteristics of acoustical sensation
1) pitch,
2) quality or timbre
3) loudness.
5. Weber-Fechner’s law
6. Curve of a level of loudness
7. Audiometry
Literature
1. Raymond A.Serway, Jerry S. Faughn Colloge physics, Fifth Edition.-Saunders College
Publishing.- 1999.-1029 p.
2. Marzeniuk V.P., Diduch V.D., Vakulenko D.V. et al. Biophysics and medical informatics.Ternopil: Ukrmedkniha, 2004.-480p.
3. Hugh D. Young, Roger A. Freedman University physics with modern physics, 11 th edition.Pearson education.-2004.-1714p.
4.Frank J. Blatt Modern Physics .-McGRAW-HILL, INC.-1992.- 517 p.
5. Methodical instructions (indication) for student’s preparation, lecture.
Questions for self-preparation of students:
1.What is the sound?
2.Classification of sound.
3.Objective characteristics of sound:
4.What is harmonic spectrum?
5.Subjective characteristics of acoustical sensation.
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6.Scale of a level of intensity.
7.Weber-Fechner’s law.
8.Curve of a level of loudness;
9.The testing of hearing.
Tests.
1. Point out right formula which is described Veber-Fechner law
I
I
E  k ln
E  k lg 0
I0
I
I
I
Ek
I  k lg
I0
I0
Е – level of volume, І0 – threshold of intensity, І – given intensity, k – coefficient of proportional
(aspect ratio) which depend on I and v.
2. Sound is:
a) Mechanical waves with frequency below 20 Hz
b) Mechanical waves with frequency between 20000 and 109 Hz
c) Electromagnetic waveswith frequencyвід between 16 and 20000 Hz
d) Mechanical waves with frequency between 16 and 20000 Hz
3. Basic characteristics of sound:
a. loudness, phase, tone
b. phase, timbre, density
c. intensity, frequency, propagate velocity, mass
d. tone, refractive index, permittivity
4. Human ear may perceive sound with frequency from 20Hz to 20000 Hz. Determinate length
sound wave range relate to hearing interval. Speed of sound =340 m/s.
Class independent work
Audiometry
The research will be carried out in a special cabin or sound isolate a room. Through headphones
or telephones for inswide of ear the doctor shows to the patient sounds of various frequency and
loudness. The patient, in turn, pressing on the button, informs to the doctor that the sound is heard.
On the following investigation phase the sound moves not through headphones, and through, socalled, bone the vibrator, available on foreheard or on bone for by ear. Results of research the
doctor puts on audiogram. The horizontal lines on audiogram designate sound frequencies, vertical
lines - intensity of a sound in dB
The testing of hearing is most often carried out by establishing the threshold of hearing, the
softest sound which can be perceived in a controlled environment. It is typical to do this testing with
pure tones by providing calibrated tones to a person via earphones, allowing that person to increase
the level until it can just be heard. Various strategies are used, but pure tone audiometry with tones
starting at about 125 Hz and increasing by octaves, half-octaves, or third-octaves to about 8000 Hz
is typical. Hearing tests of right and left ears are generally done independently. The results of such
tests are summarized in audiograms.
Audiograms compare hearing to the normal threshold of hearing. On each frequency the
difference of a level of intensity in a pathology and norm answers a difference of a level of
loudness, that is sensation of the same sound in norm and pathologies. This difference in norm and
pathologies refers to as loss of hearing. Loss of hearing is decrease of a level of loudness
perception the patient of a sound of the given frequency (a level intensity) in relation to norm. Loss
hearing is accepted to estimate on increase of a level of intensity in comparable with norm. . For an
estimation of loss of hearing to be under construction audiogram. Audiogram is a diagram, which
show loss of hearing in decibels on frequency oscillation.
Audiometer АП-02 generates frequencies clean tones: 125, 250, 500, 100, 2000, 3000, 4000,

position scales “ Drop hearing, dB” for all frequencies answers a threshold of acoustical sensation.
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