Deafness Research Project BY
Y. P. KAPUR* Christian Medical College, Fellore.
In India there are no statistics available on the number of hard of hearing or deaf patients. Isolated surveys carried out by the Ministry of Education of the Union Government in Bombay', Kanpur and Delhi' give figures which are too scanty to draw any conclusions from. There are no figures available in India on the major causes of hearing loss in our population. There is no data on the role the Tropical Diseases play in causing hearing losses though Typhoid, Kala-Azar and Brucellosis have been blamed. No proper study has been carried out to investigate the role of viral diseases like Mumps, Measles, Chicken-pox and Small-pox in causing a hearing loss. A study of the world literature on hearing loss shows a dearth of literature on this subject. In order to study the role Infections and Tropical Diseases play in causing hearing losses a Deafness Research Project has been started in Vellore. This project is being sponsored by the National Institutes of Health in Washington, D.C., U.S.A., and in collaboration with the Johns Hopkins Medical School, Baltimore, U.S.A. Dr. John E. Bordley, Professor of Oto-Laryngology and Dr. William Hardy, Professor of Audiology, are the collaborators of this programme in the U.S.A. The aims of the study are : (1) A prospective study on 1,500 school children between the age group of 5 years to 14 years is being carried out. These children are carefully selected. They have normal ear, nose and throat findings, normal *Associate Professor of Otolaryngology and Director of the Project.
72 Y. P. Kapur audiogracns and a careful history is taken of their past illnesses so that any child who is a ' risk ' in developing a hearing loss is not taken on this normal pool. This history also allows the rejection of children, who have developed most of the illnesses under study, in the past. The children are selected from the rural and urban schools in and around Vellore. Once they are put on the normal pool they are followed up every day by specially trained social workers. In this way any child that develops any illness is immediately brought to the hospital where he is investigated and a diagnosis made of his illness. At the same time he has a complete otolaryngological and audiological examination done. Thus it is possible to correlate the particular illness the child has had with otolaryngological and audiological changes. It is hoped that when this study is completed the role the various Infectious and Tropical Diseases play in causing hearing losses in children will be established. A retrospective study is not possible in India as it is very difficult to get a reliable history from illiterate patients. (2) At the same time the clinical course of the infectious and tropical diseases is studied by carefully following patients with these diseases in the hospital. This enables one to study at what stage of a particular illness a hearing loss develops and its correlation to otolaryngologic and audiological changes. (3)
In patients who die of these diseases, temporal bones are being removed. At the present time there is no Pathological Laboratory in India which can section temporal bones. These bones are sent to the Otology Laboratory of the Johns Hopkins Hospital for
Deafness Research Project
73
sectioning. With these sections it is hoped to build a library of slides for teaching the pathology of deafness in India. (4) Methods of screening young Indian children have been developed and will be published shortly, (5) A training programme for audiometric technicians has been started and the project is in a position to train personnel from all over India. (6) A rehabilitation center for the hard of hearing is in the process of being set up. Facilities will be available for giving speech reading and auditory training to patients needing this. Procedures for fitting and evaluating the various hearing aids have been set up and are available to patients from all over India. FACILITIES AVAILABLE
A good sound proof room was the first thing to be built. The figures by the Ministry of Health in their Circular No. F.2-46/MIII 4 dated the 29th September 1961 regarding the cost of building of Audiological units in E. N. T. Departments are exaggerated. The sound proof room that was built here was built for less than Rs. 3,000/-. Its specification are given below and it is suggested as a model for the building of sound proof room in the hospitals in India. The sound proof room at the Christian Medical College has the following features. The hearing test room has the following dimensions .— Height _ 8 feet Length - 9 feet Breadth - 9 feet
74
Y'. P. Kapur
Deafness Research Project
75
These are the inner dimensions. This is a room within a room There is an outer 9 inch thick brick wall. Since there should not be any contact between the outer wall and the inner wall, a 2 inch air space is left between walls. Then there is an inner brick wall, 4 inches thick all round. The two walls and ceiling structure are completely isolated from each other all round by a 2 inch air space except where the door of the room is. There are two wooden doors for this room with the edges lined by felt to seal properly and provide good acoustic isolation. The inner door faces inwards and the outer door faces outwards. These doors are made of solid wood. There is a wooden bridge to bridge the gap between the two doors. There are no windows in the room. Ventilation is provided by an air conditioner outside the room facing the inner room. The air conditioner is kept on during the time the sound proof room is not being used; the doors of the room are kept open at all times to keep it cool. When a hearing test has to be done then the air conditioner is put out to avoid the noise it causes and which will interfere with the testing. A good acoustic engineer can provide air conditioning of the sound proof room by using a system of baffles and acoustical treatment of ventilating ducts leading to and fro from the room, but in India these engineers are hard to find. The inner walls of the hearing test room are lined by Acoustic tile. Acoustic tile helps in securing maximum quieting of sounds arising inside the room and those arriving from outside. The floor is carpetted. Carpetting of the floor is essential to reduce impact and scrapping noises inside the room. Lighting is by a fluorescent lamp. Care must be taken to design this fixture so that the hum from this lamp is avoided. A small window with double glass is provided in one of the walls for observation. An 18 inches fan placed on the floor of the audiometry room facing the door to help circulate the air and for ventilation. The present room is isolated all round except the floor. It is built on the first floor. However, it is recommended that all sound proof rooms be built on the ground floor as
76 Y. P. Kapur isolation of the floor is technically difficult. These rooms should be located in a quiet corner of the hospital away from all plumbing noises and waiting halls. Preferably Acoustic survey of the area where the room is to be built should be carried out. Measurements made in the room by a General Radio Sound Level Meter Type 1551-B show that at peak hours of the outpatient attendance the overall S.PL does not go above 40 db thus keeping within the levels of sound permissible in audiometric room as laid down in the American Standards Association publication '. ,
Two Amplivox Model 81 C Audiometers which have fully tropicalised are being used in the project. The other special feature of these audiometers is that they have auxiliary 30 db precision attenuation placed in the earphone lines capable of measuring hearing levels down to 30 db below the British Standards Zero and have speech attachments for use in speech audiometry. The Imperial Surgical Company Private Limited, India House, Fort Street, Bombay-1, has full facilities for Acoustic and electrical calibration of Amplivox audiometers. This is only a preliminary report and will be followed by a series of reports on the findings and results obtained as the study progresses. The project will accept from any Otolaryngologist interesting tested temporal bones for sectioning and traced section will be sent back to the institution or person sending such bones with a detailed report. The literature on proper removal and storage of temporal bones is available from the project on request. The project will also accept patients from any where in India who have hearing defects following any of the illnesses mentioned in the beginning of this paper.
Deafness Research Project
77
REFERENCES 1.
Bombay Random Sample Survey of the Handicapped, conducted by the All India Occupational Therapists' Association on behalf of The Central Advisory Council for the Education of the Handicapped, Ministry of Education, Government of India- 1957. Published by Smt. Kamala V. Nimbkar, At A. I. O. T Association, Victoria House, Victoria Road, Byculla, Bombay-27.
2.
Report on A Random Sample Survey of the Handicapped in Kanpur by Dr. R. N. Saksena, Ph.D., D.Litt., Director, Institute of Social Sciences, Agra University (financed by Ministry of Education, Government of India).
3.
The Handicapped in Greater Delhi, a report based on a Sample Survey of the Handicapped in Greater Delhi, conducted by the Delhi School of Social Work, 3, University Road, Delhi-B, on behalf of the Ministry of Education, Government of India.
4.
Ministry of Health, Government of India, Circular No. F. 2-46/61-MIII, dated the 29th September, 1961 addressed to All State Governments (including Union Territories) on the subject of Establishment of Audiological Units in E. N. T. Departments.
5. American Standard Criteria for Background Noise in Audiometer Rooms, S. 3-1-1960, American Standards Association, Ill East 45th Street, New York 17, N. Y.
5
