Assessment of Hearing Disability: Guidelines for Medicolegal Practice

Part 1. Introduction. Historical Background and Terms of Reference. Rationale and Philosophy, Scope and Report. Part 2. Definitions Particular to this Report. Part 3. Technical Background. General, Surrogate Measures of disability. Characterization of The Concept of Hearing Disability. Scale relation Between Autiometric Impairment and Disability. The low Fence and The high Fence. Differential Weighting of The two Ears. Age--associated Hearing loss. Part 4. Audiometric Equipment. Equipment for Air--conduction Audiometry. Equipment for Bone--conduction Audiometry. Additional Equipment. Equipment required for Calibration of Audiometers. Quality Assurance. Quality Assurance -- general. Principles of Calibration. Procedures. Background Noise Requirements for The Test Room. Specific Recommendations Applicable to Audiometry for disability Assessment. Part 5. Determining Hearing Threshold Levels in Usual cases. Audiometric Procedure -- Procedure for air Conduction Testing. Procedure for Bone Conduction Testing. Reporting of Results. Sources of Error in audiometry -- Sources of Objective Error. Systematic and Random Uncertainties associated With Audiometric Techniques. Uncertainties Associated With The subject. Normal Expectation of Audiometric Reliability. Abnormal Performance or unusual Occurrences. Uncertainties Associated With Audiometric Techniques. Uncertainties Associated With The Subject. Normal Expectation of Audiometric reliability. Abnormal Performance or Unusual Occurrences. Uncertainties associated With The Audiometrician and The Interpretation or Responses. Qualifications and Training of Personnel. Part 6. Determination of Hearing threshold Levels in Abnormal Cases. Detection of Spurious Hearing Threshold level (shtl). Estimation of Genuine Hearing Threshold Levels (ghtl). Part 7. Evaluation of Compensable Hearing Loss. Mandatory Requirements. Conditional and discretionary Tests. Principles of Evaluation. Age--associated Hearing Loss (aahl). Evaluation of a Conductive Component of Hearing Loss. Relevant conductive Hearing Loss. Evaluation of The Decibel Value of The Chl. Part 8. Tables for Calculating Percentage Disability. Source Material and Derivation. Basic Relation Between Hearing Threshold Level and Percentage Disability. Binaural Evaluation. Tables of Percentage Disability. Part 9. Assessment of disability. General Plan. Diagnosis of Noise--induced Hearing Loss. Assessment of Overall and Noise--induced Hearing Disability. Apportionment. How to use The tables. General Procedure. Procedure When There is a Constitutional Element. Part 10. Additional Assessment Procedures. Retrospective Assessment and Rules for Apportionment. Prognostic Assessment. Other Considerations. Tinnitus. Noise--induced Vestibular Malfunction. Use of Hearing Aids. Part 11 Contents of the Medicolegal Report. Part 12 Summary of Recommendations.