Improved Procedure for Determining Percentage Loss of Hearing
NAL Report No. 118, January 1988
This report presents empirical formulae and computer programs which can be used to calculate binaural and monaural percentage loss of hearing (PLH) accurately in hearing threshold level (HTL) steps as small as 0.5 dB or less. Binaural and monaural PLH tables are also presented which differ slightly from the 1974/76 tables but which give the same results as the computer programs. PLH determined by means of these new tables is at least as good a predictor of hearing difficulties in everyday life as PLH determined by means of the 1974/76 tables (see item below). The slight change in the PLH tables and publication of the International Standard ISO 7029 concerning the effects of ageing on HTL have made it necessary to prepare a revised presbyacusis correction table. Separate values of age-related PLH are required for males and females since hearing deteriorates faster as a result of ageing in men than in women. The frequency range of the new binaural and monaural PLH tables is 500 to 4000 Hz, the same as that of the 1974/76 tables, and it is recommended that this range be used for general purposes. However, there are special circumstances where a set of tables which cover the frequency range 500 to 8000 Hz are required. Tables which extend the frequency range of the PLH procedure to 8000 Hz have been prepared and are also presented in this report. This procedure is now used in all States and Territories of Australia.
Software program - Percentage Loss of Hearing Calculator This is a user-friendly Windows software, recently made available, to enable users to obtain the percentage of hearing loss without having to look up the tables in this Booklet. This software comes with the Booklet but if you already have the booklet, you may just order the software at a slightly reduced price. The software is supplied on a floppy disk, but may be supplied in the form of a CD if specifically requested.
This booklet & software program is item P4388 on the order form.
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Tables for Determining Percentage Loss of Hearing
This publication is a re-issue of the NAL binaural tables for determining percentage loss of hearing dated October 31, 1974 and the NAL monaural tables for determining percentage loss of hearing dated February 16, 1976. The NAL procedure for determining percentage loss of hearing was accepted in 1975 by appropriate committees of both the Otolaryngological and Audiological Societies of Australia as the best available procedure for assessing hearing loss on a percentage basis and percentage loss assessments obtained with this procedure were accepted by authorities responsible for the administration of the various Australian workers’ compensation statutes.
This booklet is item P4387 on the order form.
Please note that this booklet has ceased to be used for workers compensation in NSW from 1 January 2002. The NSW Government has joined the rest of Australia in adopting the 1988 Improved Procedure for Determining Percentage Loss of Hearing (NAL Report 118), which is described in the item above
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A Procedure for Determining Percentage Loss of Hearing of Clients with Abnormally Poor Speech Discrimination
NAL Report 124, January 1991
This report presents a procedure for determining the percentage loss of hearing (PLH) of clients with abnormally poor speech discrimination. The procedure provides the clinician with a means of deciding whether the speech discrimination of the client is abnormally poor and a means of converting the poor discrimination score into a value of PLH greater than that which would be obtained by applying the PLH tables to the hearing threshold levels (HTLs) of the client.
This booklet is item P4389 on the order form.
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