PRODUCTS FOR THE HEARING IMPAIRED AND FOR THE DIAGNOSIS AND TREATMENT OF THE HEARING IMPAIRED, NAMELY, TELEPHONE AMPLIFIERS, TEXT TELEPHONES, INDUCTIVE PICKUPS FOR TELEPHONE LINES AND AMPLIFIERS THEREFOR, SAFETY TRANSFORMERS, LIGHT INDICATORS FOR TELEPHONES, COMPUTERIZED HEARING AID FITTING AND TEST SYSTEMS COMPRISING FREQUENCY RESPONSE AND ACOUSTIC PATTERN QUALITY ANALYZERS; MAGNETIC FIELD STRENGTH TESTERS; AND ELECTRONIC METERS FOR THE EVALUATION OF TASTE FUNCTIONS