Public-address and Sound -recording Equipment in the School.

 


The use of radio in bringing educational programs to the school classroom has been discussed, but radio equipment also has value as a teaching device within the school. While such equipment was originally devised for broadcasting purposes, it can be used to transmit programs picked up by the receiving set, or information originating within the school itself, to various parts of the educational unit. The installation of such equipment has a double appeal-to the school administration and the faculty, and to the students and their organizations. By installing a public-address system, with a control panel and output circuits to all class and assembly rooms, the office of the principal becomes a broadcasting studio from which he can send instructions or information to any or all teachers, to every class, or to a single classroom. This is efficient in the large school where the writing of information and its delivery to individuals is a lengthy process. If an emergency telephone call is received in the school office for a teacher or student, the principal or his secretary can plug into the classroom in which the individual is and call him or her to the office phone. The public-address system can also be used for fire drills and in case of fire. Many large schools do not have assembly halls large enough to hold their entire enrollment, but, through the use of public-address equipment, assembly programs can be transmitted to classrooms, study halls, and the library. Assembly programs are always a school problem, hut, if they are piped to the various classrooms from the school broadcasting studio, they can be made to have a program interest that they do not have when given from the platform. The best in music, from recordings, can open the assembly; the speaker should be brief; an overture can introduce a skit; and, after such announcements as the principal desires to make, the broadcast assembly may be concluded with another musical selection. A small accoustically treated room adjoining the office of the principal, from which dramatic skits can be presented, is suggested. The school executives have difficulty in inducing parents to attend parent -teacher meetings, but the school microphone can easily be hooked into a telephone line and a parent -teacher program piped to a local broadcasting station. In this way the parent -teacher meeting would be sent to every parent and taxpayer. By the use of centrally controlled public-address equipment, school plays, debates, contests, and other activities can be advertised to all pupils as they are moving from class to class. The school librarian may use the service to announce new books, reading lists for special courses, and reviews. Student -council reports also can be made in this way at appropriate periods. Nearly all equipment is built so that certain switches may be reversed, with the result that the principal can listen in on any classroom equipped with a loud -speaker. This saves inspection visits, which embarrass both teacher and pupils. The value of such public-address equipment is even greater for the student than for the school administration. Educational programs picked up from the air by a receiving set in the school control room can be piped to the class desiring that program. This saves the necessity of having a large number of radio sets in the school or of moving them from room to room. A broadcast from the United States Senate, for example, could be piped to a civics class, an excellent dramatic production sent to the loudspeaker in a dramatic class. A university debate broadcast would appeal to the school team. Any classroom acoustically satisfactory for speech is equally satisfactory for reception. The wise administration or control of the use of the school publicaddress equipment is vital to its effectiveness and value to the school as a whole. Some one member of the school administration should be in charge and responsible for its use. If the equipment is overworked, if it interferes with classroom work, it will be a nuisance and will be generally condemned. Announcements should be piped only to those rooms for which they are intended. School information should be broadcast at the beginnings of the class period. The announcements should be terse. In order to avoid the excessive use of the public-address system to disseminate school bulletins, 5 -minute periods, one in the morning and one in the afternoon, could be set aside for this purpose. The equipment would be used only for emergency calls at other periods. If a teacher or a pupil is wanted in the office during the class period, the public-address administrator should first find out from the school files where that teacher or student is located and then call that classroom only. Not taking full advantage of the opportunities offered by the publicaddress equipment is just as bad as excessive use of the equipment. To use it only to replace the intercommunicating telephone system or messenger is neglecting the educational purpose of the equipment. While assembly programs will be sent over the public-address system to all classrooms, those radio programs which have been requested by an individual teacher should be piped only to that teacher's classroom. Furthermore, such program requests by teachers should be investigated by the administrator before the request is granted. Programs generally are broadcast in series, so that a program in the series can be heard and evaluated before a future one is accepted for use in the schoolroom. The individual in charge of the school public-address equipment should write to near -by radio stations, asking to be placed upon the weekly mailing list for program releases and also for information concerning the educational programs. Nearly all stations supply such information willingly to increase their listening audience. A week in advance of the programs a mimeographed list of acceptable programs should be sent to teachers, so that they may select any they desire for classroom reception. The "teacher's -aid" administrator should read items in magazines and newspapers concerning programs and be alert to request teachers' manuals, classroom guides, supplementary discussion suggestions and reading lists, and suggestions for utilizing the broadcasts. These aids were discussed in the preceding chapter. Having made up a schedule of the programs desired, the administrator will tune in the receiving set well in advance of the time of a program, warn the receiving class 30 seconds before the program, and then plug in the radio to the line that goes to that classroom only. The administrator must return to his control board to turn off the program promptly as it ends. Such a plan would not require an operator on duty at all times, but only according to a definite schedule. The equipment does not require a technically trained operator; it is as simple to operate as a telephone switchboard. Any secretary or stenographer in the principal's office can operate the control board, or students from the school radio club can take entire charge. If the public-address equipment is not desired for the entire school, portable equipment may be purchased. Such equipment will improve the reception of assembly programs in the assembly hall. It may be used to announce athletic contests upon the school field and may be used extensively for the teaching of speech courses. In the latter case a small booth or studio can easily be constructed of celotex in the corner of the speech classroom, and training can be given in microphone technique as well as in analysis in speech. The objection has been made that the use of such equipment transforms the speech class into a vocational class for broadcasting. To quote Dr. H. L. Ewbank of the University of Wisconsin: "We do not regard this course (broadcasting) as a vocational course. We consider it rather as an advanced course in voice training that will also acquaint the student with problems in the field of broadcasting." Such high-school training creates a more discriminating, appreciative, and understanding audience for radio programs. It is a mistake to think that the use of a microphone turns a speech course into a radio vocational course. The public-address system offers an excellent teaching tool in speech and dramatics. By a critical analysis of the best radio speakers the pupils can learn much concerning pronunciation, enunciation, intonation, and cadence. A student from a speech class may be sent from the room to speak over the public-address system. His classmates will be more critical of his delivery if he is dissociated from the voice they hear. As the microphone is very sensitive, any defect will be clearly heard and brought to the attention of the speech teacher. Public -speaking classes of the past were designed to train platform speakers, politicians, lawyers, ministers; today, however, the radio is the platform of the public speaker, and he needs the modernized training offered by the microphone of the public-address system. Finally, as radio speech comes into the ears of every student, microphone training is ail excellent incentive to better speech by the student. Such equipment in the public schools is an incentive and tool, not only for the speech student, but also for students in other courses. A student in English composition will strive for perfection if his essay, his play, or his story is accepted for an intraschool assembly broadcast. The civics class will endeavor to emulate "The March of Time" or the best news commentators in the preparation of copy. Dramatic classes will gain their technique as they rehearse a play for a school broadcast. This creating and participating in local programs will create interest in many classrooms. The tendency in the modern educational system is to make the curriculum as practical as possible. The introduction of radio equipment into the school is in keeping with this trend. A course in broadcasting should enlist the cooperation of classes in writing, civics, journalism, speech, dramatics, and physics. In many schools the class in physics has installed the public-address equipment for the entire school. These students also maintain the equipment and act as control operators in the school studio. Their training is practical and generally extensive enough to prepare them for a position in a broadcasting station. Students in speech will act as the school announcers as well as give radio talks. Only by practice can the student overcome mike fright and improve his delivery. Consequently, the faculty should allow students to make all possible announcements and to read school bulletins over the publicaddress system. With the aid of the other classes the teacher of broadcasting can build a weekly program that will he accepted by the local station as a sustaining program. Such a program, after being rehearsed over the school equipment, will show parents what their sons and daughters are doing in school and will advertise the activities of the school. 


When a father hears his son in a school broadcast reviewing a hook, interviewing a teacher, or taking part in a radio play, he is more appreciative of the teacher who has given his boy this training and opportunity. The person in charge of such programs and of all intraschool broadcasts should first be possessed of a sense of showmanship; second, have an interest in radio broadcasting; third, have had some speech training; and finally, have sufficient common sense to follow mechanical instructions. The experience of teachers seems to indicate that the appearance of boys and girls before the microphone contributes to their educational development. First, it develops greater interest on the part of pupils, . . . chiefly, perhaps, because the activity is so far removed from the usual academic school experience. Second, .. . radio brings the pupil in touch with the modern world, . . . placing the youth in touch with modern methods of communication. Third. . . . it is difficult to persuade a student of the necessity for good speech; when at home and among friends he is able to get along satisfactorily without it. But with his first trial over the microphone and the criticism of his fellow students, which follows, the need for effective speech is brought home to him in a forceful fashion. The case of turning out a dull program also teaches much to the student whose writing has turned to the radio field. .. . Drama can be produced over the microphone when the lack of costumes and stage settings makes it impossible for the students to appear in regular theatrical surroundings. Since scripts can be used, attention can he centered on the interpretation instead of the memorizing of lines. Straight talks and discussion groups provide opportunity for instruction in effective public speaking in the modern manner and discourage bombastic utterance. . . . Such broadcasting is possible in any school having radio sound installation.' Every school system has some teacher who is outstanding in his or her field but who cannot conduct more than one class in a term. Such a teacher can become a master teacher for a number of classes by conducting them from the school studio. The unique or outstanding method may thus be observed by other teachers while their pupils are receiving instruction. Those students who have the opportunities offered by the publicaddress equipment receive excellent training in (1) correction of speech defects and improved diction, (2) self-control under tension, (3) poise, (4) naturalness, (5) joy of achievement, and (6) punctuality.

 

I come from an industrial center and the speech problem there is a critical one. We have many students who won't talk. They are listed as a "backward" group, due largely to their inability to express themselves. We have students, coming from the poorer section of the city and of foreign extraction, who have a decided dialect in their speech and for that reason they are extremely self-conscious. They, like the rest of the world, have become speech -conscious. They realize that they do not speak in the same manner as do students from American families. However, this type of speaking has become a habit with them and they seem unable to break it. They are ashamed of this defect, but they are reluctant to take a speech course or to speak in any other course because they do not want to be laughed at. Another group of backward students that needed speech training consisted of those whose vocabulary was such that they could not express themselves adequately and were, therefore, reluctant to express an idea even if they had one. They had not had contact with good books or good speakers. Whether this was due to a lack of facilities or a lack of desire and incentive, I cannot say, but prob- ably all played a part in making them deficient in language. The third group in this division consisted of those who had the knowledge and equipment necessary to be successful students but who were so shy and retiring in their nature that they could not force themselves to get up in class to recite. They were so frightened that the mere mention of a speech class sent shivers of horror up and down their spines. These three groups constituted a section of the student body that needed speech, and yet it was also the section that was least likely to take it. The prob- lem was to think of something that would motivate them to take speech in high school and to arrange a situation that would not be too antagonistic to their sensitive natures. It was then that we hit upon the idea of the public-address system. There were several things about this that made it especially adaptable to our needs. It had several qualities about it that would make it easy to sell to this type of student. In the first place, it was novel-it had a sort of glamour to it that appealed to the student; then, too, they could give their speeches from pre- pared manuscripts; and finally, they did not have to face their audience. Now I realize that this, in most cases, is considered a handicap, but that was not true in this instance. These students dreaded to face an audience, but when they could go into a little room all by themselves and deliver their speeches from prepared manuscripts, some of their dread left them. These were some of the arguments that we used in arousing the interest of the students and by dint of much per- suasive speaking on our part and on the part of the class advisers we managed to get together a class which we called "Broadcasting." Now this class was probably one of the most disheartening groups that ever confronted a teacher. For the first two weeks they were so shy, even of one another, that they would not look at each other. They would look out of the window or at the ceiling or bury their heads in their hands. To alleviate this situation the instructor secured a book of boners that had been made on the radio, some of them by outstanding announcers. Many stories concerning the self-consciousness and nervousness of great speakers were also related. These anecdotes broke the ice somewhat and created a feeling of kinship, not only among themselves but between them and the other people who made speeches. Then the "mike" was introduced. A bare outline was given concerning th
the speaker must influence his hearers individually rather than collectively and this was just the type of training that these students needed. They learned the art of conversation through the medium of the microphone and therefore in this school the public-address system paid for itself by proving successful in this one experiment. Schools which have installed public-address systems report that these systems have been paid for by boards of education, student -body organizations, or parent -teacher organizations. In every instance the officials believe that the expenditure was justified. They report an average maintenance charge of only $21 a year. In a survey on the "Effectiveness of Sound Distributing Systems," conducted by G. N. Kefauver and H. C. Hand, 97 per cent of the 324 school administrators reported that such equipment was more than satisfactory. It is difficult to advise the installation of any particular type of equipment because such systems are being improved from year to year, but certain recommendations can be made. All claims of the salesman should he investigated by someone, who understands the technical end of sound transmission and reproduction. The controls must be simple and durable. Maximum flexibility in output is desirable in order to give the greatest service to all parts of the building. The amplifier should have an undistorted and uniform output from 50 to 8000 cycles per second. Arrangements should be made so that volume can be controlled to a limited extent at the listening points. There should be visual indication of volume on the control panel. Buzzer systems should be installed in classrooms to silence the class for the forthcoming program. The main panel should include a monitoring loud -speaker. Provision should be made to transmit phonograph recordings by a turntable, with both speeds, and an electrical pickup, also for telephone connections. The acoustics of rooms in which speakers are located should be considered in the placing of such speakers. The microphones should be of a high quality. Studios to be used by speakers may need to be acoustically treated or may he satisfactory as they are. In many instances a school will not desire a public-address system serving all classrooms but will use such equipment only in its speech department. In such an instance the playback of a sound -recording machine may be used, thus combining two useful aids to the teaching of speech. Only the microphone, pre -amplifier, and loud -speaker units would be used for a schoolroom public-address system. 


Recording is a process of cutting or impressing sounds on film, steel tape, wax cylinders, dises made of aluminum or acetate, or thick wax discs so that they may be reproduced at some future time. The recordings upon film and upon tape are excellent in some respects; when sound film is used in connection with a picture, the posture and mouth action of the speaker can be observed, and in the case of recording on tape the sound can be instantly erased for other recordings. However, these methods and equipment are expensive and not generally used in the schools. The recording upon cylinders is economical because the soft wax may be shaved after recording. However, such recordings are not permanent and can he played only upon a machine similar to the recorder. The recording upon discs is most generally accepted because such recordings may be played upon any ordinary phonograph or may be used as electrical transcriptions for broadcasting. 

Presto Recording Corporation.

The metal or aluminum discs are much cheaper to use, but they are more inclined to scratch. Acetate, celluloid, or treated discs give better reproductions but are more expensive. There are various discs which are quite permanent and which may be played many times before they become worn. There are a number of very satisfactory sound -recording machines upon the market; the purchaser should examine the business reputation and the financial responsibility of the manufacturer as well as the technical excellence of his product before purchasing (see Figs. 33 and 34). There are certain general requirements of recording equipment which should be considered by the prospective purchaser. It is advisable to seek the advice of some technically trained physicist or electrical engineer in the selection of equipment. The instrument must contain the latest developments, and it is advantageous to demand an agreement that the company keep it in repair for at least six months after purchase. New developments are constantly being added to the equipment. While the best
practice is to install the recording equipment in an acoustically treated studio and to make all recordings under the best possible conditions, it is nevertheless advisable to select portable equipment when purchasing. Portability permits the recording of assembly talks and musical programs, and a single outfit may serve a number of schools. The various parts of the equipment should not weigh more than a man can carry easily and should have comfortable handles; the lids should be hinged so that they can be removed and laid to one side when the equipment is in use.

 
Radio Corporation of America.



The operator should demand a blueprint of the construction of the entire equipment, to which he can refer in an emergency, but ordinarily repairs should be made by the manufacturer. Anyone using ordinary care can learn quickly to make good recordings even though it is a highly technical operation. The teacher -operator must study carefully all instructions, avoid haste, and be methodical in the operation of the equipment. Repair bills for the equipment are low. Tubes should be tested after every 1000 hours of use but generally are good for longer periods. Briefly, the requirements for such equipment are fidelity of reproduction of all speaking -voice frequencies, sturdy construction, dependability of operation, portability, and simplicity of operation. The main elements comprising such a recording system are a microphone, an amplifier, a turntable, a cutting head, and some means of feeding the cutting head across the record; also a playback arm, and a loud -speaker to be used with the recording amplifier to reproduce records. The microphone is used to convert the sounds into electrical vibrations; the amplifier increases or amplifies these vibrations to a point where they are capable of producing motion of the cutting needle or stylus. The feeding mechanism moves the cutting head radially upon the disc from the inside out, or from the outside in, so as to produce a uniform spacing of grooves. The ordinary turntable, used for playing records in any home, is not satisfactory for recording purposes. Extreme stability, freedom from vibration, and, most important of all, constancy of speed are necessary for recording. It is necessary for the motor to have mote power and better mechanical construction than is found in ordinary playback machines. Various methods, friction, belt, or gear drives, are used to rotate the turntable. Such drives must be reliable, absolutely constant. The method of shifting from 78 to 33% revolutions per minute should be simple. The turntable should not be less than 12 inches in diameter. If the school funds permit, a double turntable should be purchased so that there may be continuous recording of long programs, such as plays, addresses, or musical selections. The turntable should be accurately balanced and mounted to assure constant speed and nonwearing operation. No turntable should ever be accepted with a variation of more than 0.5 per cent in its peripheral speed while operating under load. Most recording machines today have satisfactory drive mechanisms. The grooves are cut in the acetate or metal by means of a needle which is held in the cutting head by a small thumb screw. Needles used are steel, steel alloy, stellite, and sapphire. Good steel needles cost about 30 cents and are satisfactory for ordinary recording. The life of a needle is determined by the amount of scratch which appears on the record when played back. The steel needle produces more scratch than any of the other types. When the scratch becomes too noticeable, it is advisable to use a new needle. The price of a steel needle does not warrant its being resharpened. There are several alloy steel and stellite needles on the market today which are very good. They last longer and give better results than the ordinary steel needle. The sapphire produces hardly any scratch when it is new and gives longer service. In using sapphires, it is necessary to handle the cutting mechanism with extreme care. The point of the needle is very easily chipped, and when chipped it must be resharpened. Stellite and sapphire needles may be resharpened by the manufacturer. Sapphire needles list at about $6, and can be resharpened for $2.50. The stellite costs $1.50 and can be resharpened for 60 cents. The usual life of a steel needle is about 30 minutes of cutting time, while a sapphire will cut for about 6 hours. The life of a needle cannot be positively stated because it depends on the amount of scratch you are willing to tolerate. Although the initial cost of a sapphire is much more than that of steel needles, the cost per record is about the same. A beginner should first practice with steel needles and when he becomes proficient in the use of these needles try a sapphire.
The purpose of a cutting head is to transform electrical energy into mechanical energy; in other words, to synchronize the vibrations of the needle with the sound vibrations. The price of a recording head depends on the purpose for which the equipment is to be used. If the machine is to be used primarily for the recording of speech, the cheaper recording heads will serve the purpose satisfactorily, hut, if high-fidelity musical records are to be made and the equipment in general is of high quality, a high- fidelity cutting head is recommended. The cheaper head does not record the lowest frequencies of speech or of music, or the highest frequencies produced by a soprano, a violin, or a flute, with so much volume as it records the middle frequencies. Sound is produced by vibration; frequency is the rate of vibration. A good bass singer uses a frequency range from about 85 to 250 cycles per second, while the range of a soprano is from approximately 240 to 1150 cycles per second. The range of a piano is from 26 to 4100 cycles. The violin produces notes from around 192 to 3100. These frequencies are only the fundamental frequencies; there are overtones (overtones are multiples of the fundamental) which are higher. A high-fidelity recording head will record frequencies as high as 8000 or 10,000 cycles. If high -quality musical records are to be made, it is better to buy an excellent cutting head when the equipment is purchased. Manufacturers also provide, upon demand, separate cutting heads to be used upon metal discs and upon acetate discs. For recording, there are aluminum discs; discs with a cardboard base, covered with acetate or like material; and aluminum discs coated with acetate. The recordings made on aluminum have more scratch than any of the other types. Since the cardboard -base discs are flexible and frequently warp and their surface is not so smooth as that of the aluminum - base discs, recording upon them will be of a slightly inferior nature. The best recordings are made on heavy -gauge aluminum -base acetate discs. The thickness of the aluminum used for these discs varies. In order to make cheap discs, the manufacturers have used very thin aluminum. Since these discs are flexible, they also warp. For precise work, the thicker discs are recommended. The usual recording speed for records 12 inches or smaller is 78 revolutions per minute. Transcriptions, which are usually 16 inches in diameter, are recorded at 3313 revolutions per minute. The playing time of a record also depends upon the spacing of the grooves. The table on page 235 gives the sizes and playing time for commercial discs. Recording machines are equipped with a volume control, which is used to vary the amplitude of the cutting needle when recording and to adjust the volume of the recording when played back, and a tone control, which is used to make the reproduction sound less harsh or more mellow. Actually, this tone control makes the higher tones less predominant. In some recorders, this tone control is in operation during recording and on
other machines it is in operation only when playing hack a record. Upon each recorder you will find some means of measuring volume. Some recorders are equipped with meters or volume indicators, and the proper volume is that volume which makes the needle swing to zero about every 20 seconds. Other machines are equipped with an electrical eye like that used in tuning certain radios. Different volumes decrease or increase the size of the colored wedge; the min inmm-sized wedge should be striven for. Place the cutting needle in the cutting head so that when lowered to the surface of the disc, the needle will be vertical to the surface of the record. This can easily be determined from the side of the cutting head. When the needle is vertical, the shadow of the needle on the disc and the needle itself will appear to be in a straight line. Some disc manufacturers recommend the placing of the needle at an angle of 85 degrees, measured between the needle and the part of the record which is approaching the needle point. 


When you are thoroughly familiar with the controls and are ready to try your first recording, take a new disc from the package, being careful not to touch the surface of the record, and place it upon the turntable. If you are recording a speech, place the microphone about 15 inches away from the person speaking and, after a voice test, adjust your volume control so as to give the recommended volume in accordance with the instructions from the manufacturer. Start the turntable, lower the cutting head, and let the turntable revolve and make a cutting about % inch wide. Never lower the cutting head before starting the turntable. If the needle is in contact with the record when the machine starts, the sudden jerk produced by the starting of the turntable makes the cutting head bounce and usually results in chipping the sapphire stylus. The operator must also remember to raise the cutting head before it reaches the outside of the record, when recording from the inside out, or before it travels to its limit, when recording from the outside in. If this precaution is not taken, a chipped needle will result. The size of the shaving should be approximately the size of a hair. The depth of cut and the volume which you are recording on the disc is best determined by the use of a microscope to see that you are not cutting through the acetate. After you have the adjustment approximately correct, cut a small sample of speech or music and play it back, noticing the quality. If the playback needle will not follow the grooves, you are not cutting deep enough, and, therefore, you should increase the needle pressure. When making these trial cuts, always note your maximum volume on your volume indicator and adjust the volume control so that the needle swings to the correct position according to your instruction pamphlet from the manufacturer. After a few trial cuts on a record you will become accustomed to what volume is necessary and to the size of the shaving. There is no substitute for experience; therefore, experiment, trying various steps of cuts and various volumes until a satisfactory set of adjustments is determined upon to result in good quality. It is easier to make recordings by recording from the inside out (starting near the center of the disc), because the shavings will then be behind the needle and will not interfere with the cutting. It is necessary to brush the shaving lightly toward the center with a small camel's-hair brush. Transcriptions are most frequently recorded from the inside out, while phonograph records are always recorded from the outside in. Records recorded from the inside out cannot be played on automatic record changers and in many cases cannot be played on machines which stop automatically when the needle reaches the center part of the disc. The companies will provide equipment that will make it possible to record from the outside to the center. Frequently the small and light acetate records slip on the surface of the turntable, and it is necessary to place a weight in the center if the machine is not equipped with small pins which fit into more than one hole. An excellent instruction book for the beginner is Techniques of Recording by F. H. Goldsmith and V. A. Geisel, published by Gamble Hinged Music Company of Chicago. If one desires several copies of a record, it is necessary to have a second turntable. The best copies are made by feeding the output of the playback arm directly into the second recording machine. When a large number of copies are desired, they are made by a special stamping process by a manufacturing concern from a master record. Reproducing needles for playing the finished recording are steel, special alloy steel, cactus, bamboo, and sapphire needles. Only, those steel needles which have been shadowgraph-inspected should be used. A shadowgraphed needle is one inspected by placing it in a strong light beam and magnifying the image on an elevated screen upon which is drawn the contour of a perfect needle. If the shadow conforms to this contour, then the needle is acceptable. If a flat space is seen on the shadow, the needle is rejected. When a needle becomes worn, it should be thrown away. Once a needle is taken from the playback arm, it should never be reinserted
If it is replaced, the worn side of the needle takes on a different position and becomes a chisel which cuts the record. Do not economize by using a needle too long. It is better to throw away a needle which has played only a short time than to use it too long and ruin expensive records. When playing acetate records, always notice the light reflection from the record. If there is a marked difference between the reflection of light from the part which the needle has just passed over and that from the part of the record which has not yet been played, the probability is that you have a dull needle. Also notice if there are any small shavings accumulating at the needle point. In these instances, it is advisable to install a new needle. A too heavy playback arm will also ruin the record. Cactus and bamboo needles are not recommended for acetate recordings as their points wear rapidly and soon become blunt, causing the thicker portion of the needle to spread or push aside the grooves, distorting the reproduction on the next playing. The purpose of cactus or bamboo needles was originally to produce more mellow tone or reduce the higher frequencies. Most radios and recording machines today are equipped with tone controls which accomplish this; therefore, it is best to use a good grade of steel needle. There is also a sapphire playback needle, a sapphire inserted in the end of a small metal shank. This needle will last much longer than a steel needle, but the needle must not be removed from the playback arm until its life is finished. If the needle is removed and replaced, the worn portion of the needle will act as a chisel and ruin any records that are played. Since it is hard to determine when the end of a useful life has been reached, steel needles are recommended for average use. In many commercial recording machines in the higher price range, permanent diamond points are incorporated in the playback head. These needles last indefinitely if they are not injured mechanically. Acetate records are soft in comparison with the standard phonograph record, and, therefore, extreme care must be used in placing the needle upon the record and in removing it at the proper time. If the needle is forced across grooves when placing or removing the playback arm, the result will be a scratch. Because of the softness of these records, the playback arm must rest lightly on the record so that the needle can vibrate freely. If there is too much needle pressure on the record, the record will wear out extremely fast. Also, if the needle offers a great deal of resistance to vibratory motion, it tends to eliminate the higher frequencies. For acetate records, a needle pressure of 2 ounces or less is recommended. Recently there has been placed upon the market a playback arm having a needle pressure of much less than this. The light pressure is obtained by using a small sapphire needle, which vibrates a small mirror upon which is focused a light beam; the mirror reflects this light to a photoelectric cell, from which the electrical variations are amplified in the usual manner. Since the needle pressure of this playback arm is much less than the pressure used on playback machines for the home today, this method will result in longer record life and in fewer scratches on the records. These playback arms are very satisfactory for use with acetate records. Few people realize the care necessary in handling records. A record should never be picked up with one hand so that fingerprints are left on the record. Always handle a record by picking it up with two hands, one on each side of the record, and touch only the edge of the record beyond the recorded limits. Fingerprints result in a dry, hard film, and, when the record is played, cause added scratch and noise. Records should be stored to avoid bending or strain. If slight warping occurs, it may be corrected by laying the record under a weight on a flat surface in a warm place. Never put a record on a radiator. The paper folder in which a record usually comes helps to prevent scratches. Records should always be kept either in these envelopes or in an album. When storing records in albums, always place them in a vertical position. Never leave them for any length of time lying flat with other things piled upon them. The best way to store acetate records is to place them in the tin boxes in which they come, separated by a thick paper washer. The accumulation of dust in the grooves of any disc record results in added scratch and surface noise. Commercially made records are usually of a shellac compound, while transcriptions for radio stations are made from vinyl acetate. Vinyl - acetate records are more expensive but have considerably less surface noise than the shellac records. Sound -recording equipment can be used for exercises in voice. At the outset the student is better off if he confines his work to the interpretation of the works of accepted writers. The reading of a selection of prose or easy poetry, with special attention to thought groups, will be the first test. After a brief rehearsal, before he can commit to memory the interpretation of his instructor, his voice should be recorded. It is possible to have a student make two or three recordings upon each side of the disc. 'l'he second may be made two weeks later to show progress in the recognition of word or thought grouping. In neither of these first two recordings should any attempt be made to work with other aspects of the voice. 'l'he third recording may concern itself with a demonstration of clarity of enunciation. A student with "breathy" speech can be placed close to the microphone and his defect amplified for his own hearing. The results of the difficulty are so apparent that renewed effort will be made upon the part of the student to practice prescribed relaxation exercises. Not only is the use of amplifying and recording apparatus an excellent aid to analysis, but it may also serve to record deliveries for other students to emulate. T found the Sound Mirror, a tape recording machine which plays back a 1 -minute speech repeatedly or which may be stopped momentarily at
any spot for analysis, a great help and interest creator in classes. It was so simple to operate that the students ran it themselves. Unfortunately, it is expensive equipment. Recording apparatus is most valuable in work in enunciation. Failure of the student in speech work in this field is sometimes due to structural difficulties, but more often it is due to lack of interest in good performance. The hurried chewed -up type of speech that comes from nervousness and the slower type that comes from habitual oral inactivity are seldom apparent to the speaker himself. His friends learn to lip-read or to piece together the intelligible parts into a reconstructed whole. The speaker can be made to recognize his fault by listening to a recording long after he has forgotten what he originally attempted to say. In this connection I quote from an article by Charles O'Donnell Bennett which appeared in the Chicago Tribune on March 8, 1986: The most pitiless critique of o'er -confident notables coming newly to radio is a phonograph recording of them as they speak into the microphone. The sensible ones, who can bear the shock, say: "Good heavens, am I as bad as that!" "Not as bad," the patient director replies, "but the microphone makes you sound that bad. It is as cruel as an enlargement of a poor photograph." Those not so sensible say: "That's an atrocious recording." "Possibly," the director grants, "but the atrocity is fundamentally your doing and not the record's." Dudley Crafts Watson, art critic and lecturer, was shocked by what a record made of his some- what overprecise diction. But he did not sulk. He modified. Recording equipment has many other uses in the school besides its service in speech classes. It may be used for research in phonetics and linguistics. Recordings may be made of the correct pronunciation of foreign languages, which the student can use in study periods when the teacher is not available. A debate coach in a Michigan high school, who was training his team for a state-wide contest, tuned in on a university team debating the same question. He recorded the university debate as it was picked up by the recording -equipment microphone and used the record to demonstrate points to his local group. Radio programs, such as Shakespearean plays, which conflict with school class schedules, can be recorded for future use. Musical organizations may make records for analysis. I found that it was difficult to obtain funds for the purchase of equipment at the University of Michigan until I convinced the authorities that. recordings could be made of the University Band and Glee Club and of talks by the president and other members of the faculty, all of which could be sent to distant alumni groups as complete programs for their meetings. In every instance the president addressed his recorded talk to the group receiving the disc, which created a favorable impression. Thus the sound -recording equipment can be made self-supporting. Students make records and own them at the end of the semester. The student pays for the cost of the disc, for the cost of the cutting needle, and a small charge for overhead. Members of the faculty make records to be used in research at the retail cost of such records, which allows the recording fund a 10 per cent profit inasmuch as it orders records in large quantities. There are other sources of income to make the recording equipment pay for itself. At Christmas and Mother's Day and upon birthdays, students who are away from home make records of their voices to be mailed to distant parents to be used upon the home phonograph. Local singers and musical groups make recordings to demonstrate their ability when seeking a job. Students who intend to teach speech or dramatics frequently send such recordings with their letters of application. Members of the faculty find it advisable to check up on their lecture delivery. Parents frequently record the voices of their children to bring back memories in future years. Some merchants who were in the habit of using barkers to bring customers into their stores have made records instead, which they play over a loud -speaker either in front of their shops or on sound trucks on the streets. The Committee on Scientific Aids to Learning, 41 East 42d Street, New York City, issued a pamphlet on Sound Recording Equipment for Schools in 1940. Every teacher using recording equipment should write for this instructive free book and the other research issues on Broadcast Receivers and Phonographs for Classroom Use, and Central Sound Systems for Schools.

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