AUDIO VISUAL AIDS

AUDIO—VISUAL AIDS:

Teaching learning process revolves around two main elements—teacher and taught. They act like two poles allowing an exchange of ideas and communication between them. Whatever a teacher delivers through this communication must be clearly understood and used by the pupils. For this uninterrupted flow of communication support between teacher and taught is essential. An outstanding development in modern education is the increased use of more than one sensory channel helps to clarify facts, concepts, interpretations and increases knowledge. These supplementary devices arouse interest among pupils and enrich the imagination of children.

In the past, most teaching depended almost entirely on verbal communication between the teacher and student, or written communication to the student from print materials. Although, those communication channels continue to play important roles in the learning process, today teachers are using pictures, television, programmed lessons recorded words etc to make students understand facts , skills and attitudes.

Audio-visual aids are quite helpful in instruction. Researchers have also recommended that in education we should appeal to the mind chiefly through the auditory or visual sense organs. Since it is possible that 85% of our learning is absorbed through these. A visual will not only attract the attention of pupil but hold it as long as it appeals to the sense of sight. Visual experiences are also more effective then verbal experiences. Although the learning process uses the senses as avenues to reach our minds. It is important which sense is used to conduct the message. Experience and research have shown that the following figures are generally valid.

We learn

 

1.0     percent through TASTE

1.5   percent through TOUCH

3.5percent through SMELL

11.0percent through HEARING

83.0percent through SIGHT

We remember 

20 percent what we HEAR

30 percent what we SEE

50 percent what we see and HEAR

80 percent what we SAY

90 percent what we SAY AND DO

Audio—visual aids are different types of tools that appeal to the sense of hearing and vision and are used in the classroom for presentation of a variety of information. These materials may be used to convey meaning without complete dependence on verbal symbols are language. The basic assumptions  underlying audio-visual is that learning – clear understanding – stems from sense experience. The teacher must ‘show’ as well as ‘tell’. The aids are the stimuli for learning ‘why’, ‘how’, ‘when’ and ‘where’. The hard to understand principles are usually made clear by the intelligent use of skillfully designed aids.

Definitions of audio—visual aids:  

Burton: audio—visual aids are those sensory objects or images which initiate or stimulate and reinforce learning.

Edgar dale:   Audio—visual are those devices by the use of which communication of ideas between persons and groups in various teaching and training situation is helped. These are also termed  as multi sensory materials.

Kinder, S James: , Audio—visual aids are any device which can be used to make the learning experience more concrete, more realistic and more dynamic.

Carter V. Good: Audio-visual aids are those aids which help in completing the triangular process of learning i;e motivation, classification and stimulation.

Mckown and Roberts: Audio—visual aids are supplementary devices by which the teacher, through the utilization of more than one sensory channel is able to clarify, establish and correlate concepts, interpretations and appreciations.

The psychology of using teaching aids:

There is an old saying which reads

I hear, I forget

   I see, I remember

I do, I understand.

I HEAR, I FORGET

The traditional teacher depended too much on verbal expositions. The pupil hears and forgets. Further, the unless the individual has pragmatic imagination it will be difficult for the individual to visualize objects that events, however vivid the verbal description is. It is highly possible that concepts formed will depend on the nature of the background experience of the individual. It is necessary particularly in science and technology that knowledge gained by individual is accurate, where considerable visualization of objects and processes is needed and formation of accurate concepts is essential.

I SEE, I REMEMBER

As a sensory organ, the eye is very highly developed when compared to other sensory organs. The human eye could differentiate very minute differences in color and shade. It is quite natural that the knowledge gained through the sense of sight is more vivid, accurate and permanent. Hence, what one sees, one remembers. More than 80% of our knowledge is gained through our eyes.

I DO, I UNDERSTAND:

When one is engaged in any practical activity, involving physical work knowledge is perceived through all the senses. This is learning by direct experience. Psychological studies of effective learning emphasize the importance of first hand concrete experience involving sensory contacts as the starting point of learning. Which later only proceeds towards greater and greater abstraction. Pupil profits most instruction when he becomes involved through his own interests and purposes and such an involvement is possible when concepts and principles are introduced to him through well chosen educational media appealing to the different senses. The teacher can make use of specific audio—visual aids to suit the interests and purposes of his students.

 Advantages of Audio—visual aids

An audio — visual aid occupies an important place in teaching learning process. The use of audio—visual aids is advantageous for all the pupils. Some of the important values of the proper use of audio—visual aids are given below:

1.      Best motivators:  Audio—visual are the best motivators. They present the knowledge in the concrete form by attracting the attention of pupils. The students work with more interest and zeal.

2.      Clear images.    Clear images are formed when we see, hear, touch, taste and smell as our experiences are direct, concrete and more or less permanent. Learning through the senses becomes more natural and consequently the easiest.

3.      Reduce verbalism. Audio—visual aids help to reduce verbalism. Verbalism does not prove much effective in the process of teaching and learning. Commenting on this aspect Raymond Wyman writes.

“we (teachers)  tell students and provide them with written material so much of the time. Words are wonderful. They are easily produced, reproduced, stored and transported. But the excessive  use of words can result in serious  problem, chiefly, the problem of verbalism (using or adopting words or phrases without considering what they mean) and forgetting”.

4.      Principle of activity . the students get various opportunities of doing various activities by using audio—visual aids. When audio—visual  aids are used while teaching a lesssoon, the pupils talk, ask questions and discuss. This stimulates their various sense organs. As a result, their interest in the lesson prevails and they learn the most difficult things in a natural way without any difficulty.        

5.      Based on maxims of teaching.          These aids help the teacher to follow the maxims of teaching like ‘concrete to abstract’ , known to unknown, and ‘learning by doing’.

6.      Realism .. audio-visual aids provide a touch of reality to the learning situation. By seeing a film exhibiting the life mughal emperor Akbar pupils learn it more effectively in about 2 hours than by spending weeks by reading.

7.      Save time and energy.. A good deal of time and energy of both teacher and students can be saved on account of the use of audio—visual aids as the most of the concepts and phenomena may be easily clarified, understood and assimilated through their use.

 

Types of Audio—visual aids

For gaining full sight into the functioning and use of these audio—visual aids and equipments, we often try to classify them into some definite types and categories in a number of ways as explained below:

(1)   The first approach (traditional approach)

In traditional way, the audio—visual aids can be classified under the heads Audio aids (aids through the ear), visual aids ( aids through the eye).

Audio aids:      Audio aids mean those sources in which only hearing organs are used I;e knowledge gained mainly through ears. These aids call upon the auditory senses and thus help the learners to learn through listening to the displayed aid. The main audio aids are:

Radio – The radio as a teaching aid can play a major role in imparting instruction to school children. Some of the radio broadcasts are styled as educational broadcasts. These broadcasts are made during specific days at specific school hours, mainly for the benefit of the educational institutions. The broadcasts are on curricular subjects to help the teacher to supplement his classroom instruction.

Booklets describing  the details of programmes of educational broadcasts for the year are prepared and printed in advance by All india radio and made available to the educational institutions at the beginning of each academic year. Programmes are arranged separately for the benefit of elementary, middle, high schools and for university students.

Radio broadcasting has potentially and proves a potent source of education as they are capable of integrating education with the real life experiences on one hand and sources of entertainment on the other. The students can be easily motivated to listen to the radio talks and thus derive educational benefits.

Gramophone and linguaphone-   like radio, gramophone is a useful teaching device. It is possible to bring music, addresses, textual materials and instructional lessons into the classroom through gramophone just as effectively as it is possible through radio. Pupils can be given training for speech and music by gramophone while language is taught by correcting their pronunciation with the help of linguaphone. Every school should have a set of gramophone and linguaphone records and the teacher should use both the devices during teaching as the need arises.

Tape recorder— it is an effective recording device that cakks for yhe use of auditory senses to convey the educational message to the learners. Tape reorder is used to hear the ideas of great men, speeches of leaders and music and poems of famous on one side. While on other side pupil and the teachers can also hear their recorded voice. This helps in improving their pronunciation and correcting actual speech defects.

On account of its recording service, it may work as an effective aid for the evaluation of teaching learning programme. It may also help a teacher for the assessment of his own behavior and teaching task.

Visual aids__ In this category we may include those aids in which only visual organs are used  or applied I;e knowledge is mainly gained through visual organs.

These visual aids are further subcategorized into projective and non-projective aids.

Projected aids

 

    Project aid category include all such visual aid material and equipments that can be used for gaining knowledge about an object or event by getting it projected on a screen. When a projected aid is used, an enlarged image of the material is projected on a screen kept at a distance from the projector. The room is either totally or partially darkened. Darkened room reduces distraction and the bright image on the screen secures the attention of the pupil easily.

Projective aids are suitable for large groups as well as  small groups. The projected image could be made large and bright to enable everyone in the large group to perceive details.

Projected aid material and equipments--  projected teaching aids depend on some kinds of special equipment only then they can be used in the class. The medium through which projected aids are used in the class is called projector. They are mechanical devices assembled by certain technical parts such as lens, motor, photo—electric cell, reflector, projection lamp, projection optics etc. the material is put here in inverted position but the image formed by the material is normal.

 

Important projected devices:-

1.      Slides (transparencies) A slide is a piece of transparent surface like glass, translucent paper, cellulaose acetate film etc with drawings or pictures which can be mounted  individually for use in projector. Any picture or diagram, which will take a long time to draw on chalkboard during the class period, can be produced on a glass slide and an enlarged image of the picture on the slide can be projected on a screen with a slide projector or epifiascope. The classroom need not to be completely darkened for slide projection. There must be sufficient illumination in the classroom to enable pupils to copy down the projected diagram and take notes.

There are several methods by which slides can be prepared, the best being the photograph method. The object is photographed and the positive printed on a slide plate.

The slide on which the picture is reproduced is protected by as similar piece of glass called cover glass. The slide and the cover glasss are bound together at the edges by a piece of paper called binding strip. This binding strip is usually made of opaque paper. A piece of opaque paper (black) or metal foil is placed between the two glass plates so that only the required area is transparent.

A white paper circle is pasted at one corner to seve as indication in order to help place the slide in the proper position during, so that a proper erect image is projected on the screen.

Slide projector—Slides are projected by an instrument equipped with a powerful light source in a lamp house and carrier for holding slides of suitable sizes. Simple ‘slide projector’ was known as  “magic lantern” in the olden days. The principle here is that when we put the transparent slide on the socket and through light from behind, the light passes through it and projects the image on the screen.

A slide projector  consists of a quart, three halogen lamps, light to be reflected by the reflector, a heat filter to absorb most of the heat produced by three lamps and condenser lenses. A cooling system is also needed which consists of a fan, filter and other components. The fan is thermostatically controlled. When projector is switched off. The fan is also switched off. The slide is inserted in the inverted position but the image formed by the material is normal this is because of the objective lens placed between the slide and the screen. The slides possess tremendous educational values given below;

A)    They posses an attention focusing power which increases class interest and motivation.

B)    They can be projected in a partially darkened room thus facilitating further class discussion and note taking.

C)    A variety of printed, typed or drawn material can be presented in different colors or combinations on slides.

D)    They help to test student understanding.

II) film strips—A film strips is a piece of non-inflammable safety film 35mm wide, varying in length up to about 1 meter. It is a series of related still pictures on a single role of processed film and may contain anything from 10-50 pictures or frames. These pictures may constitute a connected series of drawings, photographs, diagrams or a combination of these and illustrate a single topic, theme or story. They may be produced in black and white or color and are sometimes accompanied by a sound track which carries narration, music and sound effects.

they are used before a large group of students either for introducing a lesson or elaborating  some minute object not seen in ordinary situations.

Film strips are projected on big screens through a film projector. It has a specially designed lamp, concave reflector to reflect light from the back of the projector lamp, heat filter, condenser frame, rotatable film carrier and coated compound projection lens. Cooling the lamp is effected by convection current or by air blower. A heat filter is also used to adsorb heat radiation from the lamp to a certain extent.