New South Wales Court of Appeal CITATION: Henry Walker Eltin Contracting Pty Ltd v Hrstic [2005] NSWCA 253 HEARING DATE(S): 15 June 2005 JUDGMENT DATE: 4 August 2005 JUDGMENT OF: Hodgson JA at 1; Basten JA at 2; Burchett AJA at 44 DECISION: Appeal dismissed with costs. CATCHWORDS: Negligence - causation - onset of persistent tinnitus - multiple possible causes - medical evidence inconclusive - whether finding on the balance of probabilities open - Non-economic loss - section 151G of the Workers Compensation Act 1987 - "a most extreme case" Workers Compensation Act 1987 LEGISLATION CITED: Supreme Court Act 1970 March v Stramare (E&MH) Pty Ltd (1991) 171 CLR 506 Bendix Mintex Pty Ltd v Barnes (1997) 42 NSWLR 307 Wilsher v Essex Area Health Authority [1988] AC 1074 Seltsam Pty Ltd v McGuiness (2000) 49 NSWLR 262 Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190 CASES CITED: Tubemakers of Australia Ltd v Fernandez (1976) 50 ALJR 720 Southgate v Waterford (1990) 21 NSWLR 427 Dell v Dalton (1991) 23 NSWLR 528 Franklins Ltd v Burns [2005] NSWCA 54 Rabay v Bristow [2005] NSWCA 199 House v The King (1936) 55 CLR 499 Henry Walker Eltin Contracting Pty Ltd (Appellant) PARTIES: Kreso Hrstic (Respondent) FILE NUMBER(S): CA 40585/04 R. Seton SC/D. Stanton (Appellant) COUNSEL: C. Barry QC/K. Andrews (Respondent) Phillips Fox (Appellant) SOLICITORS: Sowden Akerman (Respondent) LOWER COURT JURISDICTION: District Court LOWER COURT FILE NUMBER(S): DC 13331/01 LOWER COURT JUDICIAL OFFICER: Puckeridge J IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40585/04 DC 13331/02 HODGSON JA BASTEN JA BURCHETT AJA 4 August 2005 HENRY WALKER ELTIN CONTRACTING PTY LTD v HRSTIC This is an appeal from a judgment of the District Court awarding damages to Mr Hrstic and finding that his then employer, Henry Walker Eltin Contracting Pty Ltd (the Appellant), was negligent in failing to provide Mr Hrstic with a safe system of work. Mr Hrstic was employed as a project manager in a mine, which required him to work in an environment with unsafe noise levels. While he had worked in the mining industry for some 28 years and had developed tinnitus and had suffered hearing loss prior to his employment with the Appellant; during his employment with the Appellant the tinnitus became permanent. The issues for determination by the Court of Appeal included: (i) whether Mr Hrstic established that the onset of persistent tinnitus was caused by the exposure to unsafe noise levels during his employment with the Appellant; and (ii) whether the trial judge erred in finding that the severity of Mr Hrstic's injury was 30% of a most extreme case. Held as to (i) Per Basten JA (Hodgson JA and Burchett AJA agreeing): 1. Where science does not provide an explanation as to the link between a putative causative factor and a result, the question of causation must ultimately be seen as involving a question of satisfaction of the burden of proof. 2. It was open to the trial judge to be satisfied on the balance of probabilities that the exposure to excessive noise levels in the appellant's mine contributed materially to the onset of persistent tinnitus. 3. There was ample reason for the trial judge to accept that, in the absence of any contrary explanation, and accepting the proposition that high noise levels could be a cause of tinnitus, the causal connection was established. Held as to (ii) Per Basten JA (Hodgson JA and Burchett AJA agreeing): 1. The use of the indefinite article "a" suggests a class of case, rather than a specific example. Furthermore, the very nature of the exercise precludes precise assessment. At most, one can identify bands or ranges within which a reasonable assessment may be made. 2. The relevant proportion must be placed on a scale between 0 and 1, (often expressed as a percentage) where 1 is the maximum award and 0 is no award, which would presumably apply where there had been no relevant loss suffered. 3. It was not unreasonable for the trial to have picked a proportion between 20% and 30%. Whether the figure chosen by the trial judge of 30% is near to or at the top of the appropriate range need not be determined. IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40585/04 DC 13331/02 HODGSON JA BASTEN JA BURCHETT AJA 4 August 2005 HENRY WALKER ELTIN CONTRACTING PTY LTD v HRSTIC Judgment 1 HODGSON JA: I agree with Basten JA. 2 BASTEN JA: Mr Kraso Hrstic ("the Respondent") suffers from persistent tinnitus, which is variously described as a ringing or hissing sound, apparently located in the ears, though in fact constituting a neurological condition. The Respondent asserted that the condition was caused by the excessively noisy conditions in which he was required to work at the Brown's Creek Mine, operated by his employer, Henry Walker Eltin Contracting Pty Ltd ("the Appellant"). 3 The Respondent's employment as project manager at the Brown's Creek Mine commenced on 1 July 1999. The onset of the condition, identified as persistent tinnitus, was accepted by the employer as 26 October 1999, being the date on which Dr Jeff Stanborough apparently saw the Respondent and referred him to Dr Peter Bryan, an ear, nose and throat specialist. 4 Counsel for the Appellant said that acceptance of an early date for the onset of the condition was favourable to the Respondent. However, that acceptance also had a tactical benefit for the Appellant. It highlighted the real issue in these proceedings, which was whether the Respondent, with a history of some 28 years of working in the mining industry in Australia could prove to the requisite standard that his persistent tinnitus was caused by a period of some four months employment with the Appellant. 5 A second challenge, which only arises if the first challenge is unsuccessful, concerned the amount of damages awarded by the trial judge for non-economic loss. Background 6 The Respondent's history was succinctly outlined by the trial judge in his judgment of 18 June 2004. As his Honour noted, the Respondent was born on 10 August 1951 in Croatia and came to Australia in 1971. He appears to have been employed in the mining industry almost continuously from that date until the onset of his current complaint. Although there appears to have been some misunderstanding as to his period of employment with the Appellant, on the part of various medical experts to whom he was referred, it is common ground that his earlier employment was, in part, with related but different corporate entities. It was also common ground, as noted by the trial judge, that his earlier employment also exposed the Respondent to noisy conditions in his work environment. His Honour was fully conscious of the critical issue, namely whether the causal link between any excessive noise encountered during his employment with the Appellant and his persistent tinnitus had been established. Although it may not matter greatly, his Honour treated the relevant period of employment as extending from 28 June 1999 (which was in fact the date on which the Respondent signed the contract of employment) and 24 November 2000, being the date when his employment with the Appellant terminated. 7 There was no dispute that the mine was a noisy environment and that workers underground required protection from the noise. The Appellant supplied earplugs and muffs, but the Respondent's evidence, which was not the subject of significant challenge, and was accepted by the trial judge, was that he had to remove the earplugs to communicate with other workers, which, as project manager, was a significant aspect of his duties. He gave evidence that, until approximately 26 October 1999, he would spend between three and six hours underground each day. During that period he would talk to miners and had to remove the earplugs or muffs in order to understand what the men were saying. Some conversations were brief, but the longer conversations could extend to approximately five minutes. He stated that he used both earplugs and earmuffs on different occasions: the underground conditions being very hot it was sometimes necessary to replace the earplugs because they became filled with sweat. 8 There was evidence about the possibility of reducing noise levels in the mine and using a microphone and headsets so as to limit exposure to high noise levels whilst carrying on satisfactory communications. 9 Detailed discussion of this evidence is not required, because his Honour made the findings set out below, which were not challenged in this appeal: "I find that it was reasonably open to the defendant to provide further equipment or communication devices by way of a headset and that the provision of a headset may have prevented or significantly reduced foreseeable risk of injury from a noisy working environment. I also find that the defendant failed to take reasonable measures to ensure that the protection devices provided were properly fitted and secured. Such reasonable measures would involve instructions as to the proper means by which protection devices were to be fitted." 10 During the cross-examination of the Respondent in the Court below, it became apparent that there was a serious challenge to the proposition that any exposure to high noise levels could have caused the persistent tinnitus of which the Respondent complained. At least two bases for challenge were apparent. On the one hand, it was suggested that tinnitus was a condition from which the Respondent suffered prior to his employment by the Appellant at Brown's Creek. Secondly, it was suggested that the condition became a serious concern after the mine flooded on 23 December 1999, a circumstance which caused the Respondent significant stress because of the possible loss of employment and the difficulty at that time of finding alternate employment as a project manager at another mine. It was put to the Respondent that one of the medical practitioners had told him that if he got his stress under control his tinnitus may have reduced in severity. 11 A third basis of challenge in relation to causation appeared more clearly from the medical evidence. The Appellant contended that tinnitus was commonly associated with hearing loss and that, although it was accepted that the Respondent suffered a degree of hearing loss, there was no firm evidence that his hearing deteriorated significantly during his employment with the Appellant in 1999. 12 A number of medical experts prepared reports or statements which were presented on behalf of the Respondent. They were not called or cross-examined, the Appellant being, for the most part, content to base its criticism on errors in the assumptions set out in the reports. One common error was that the Respondent had been in his employment with the Appellant for a significantly longer period of time than was in fact the case. Indeed, to the extent that the Respondent's reports supported the conclusion that his tinnitus pre-dated his employment with the Appellant, the Appellant relied upon the reports itself. 13 The Appellant obtained a report from Dr Raymond L. Carroll, an ear, nose and throat specialist, who was called and cross-examined. Dr Carroll was also confused as to the Respondent's employment history. In his report of 25 November 1999, he stated: "For the past 10 years [Mr Hrstic] has worked for Henry Walker Eltin Contracting as an underground miner and for the past six years as mine manager. He works in a gold mine at Brown's Creek and currently spends approximately 2 hours per day underground. His noise exposure has come from rock drills, a mechanical jumbo drill, front-end loader, diesel trucks, ventilation fans and blasting." Dr Carroll also noted: "For about 2 years Mr Hrstic has been aware of a continuous hissing noise in both his ears." Dr Carroll obtained an audiogram which demonstrated a left auditory impairment of 13.3% and a right impairment of 10.9%. He declared Mr Hrstic fit for his usual occupation. 14 It will be necessary to refer further to Dr Carroll's evidence, to which the trial judge paid careful attention. His Honour relied on Dr Carroll in reaching conclusions with respect to questions of causation. 15 Question of "hearing loss" loomed large in the findings made below. Thus, at one stage, his Honour noted: "On the evidence before me it is difficult to determine whether or not or determine the extent of hearing loss which occurred whilst the plaintiff was in the employ of the defendant." In a second passage, his Honour appeared to assume that there had been some deterioration in hearing during the period of employment. "The evidence of Dr Carroll simply confirms the difficulty a court would have in determining the extent of the hearing loss of the plaintiff as a result of exposure to noise during the period of his employment with the defendant." It may be inferred from these passages and other surrounding discussion in his Honour's reasons that he accepted Dr Carroll's evidence that "it was not likely that [an exposure during the period of five months employment] would have made any significant contribution to the plaintiff's hearing loss". 16 Counsel for the Respondent pointed out that a lengthy report prepared by an acoustical consultant, Mr David Eden, included an opinion that the Respondent's hearing loss had increased measurably during his period of employment with the Appellant. Whilst referring to other aspects of Mr Eden's report, the trial judge did not refer to this aspect. As Mr Eden was at least ambiguous, and perhaps in error, as to the period during which the Respondent had worked for the Appellant, it is likely that his Honour was not willing to place reliance on this particular opinion. That approach would have been beyond challenge and was not, in any event, challenged. 17 Rather, the trial judge relied upon Dr Carroll's agreement "that it was possible that there be an increase in tinnitus without any increase in hearing loss". In so finding, the trial judge appears to have turned an answer by Dr Carroll that this effect was "unlikely" into a concession that it was possible. His Honour's finding was based in part upon the lack of means currently available objectively to measure levels of tinnitus, and upon uncertainty as to the aetiology of tinnitus. 18 A further complicating factor in understanding the evidence in this case is that, although it may not have been apparent throughout the trial, it was clear by the end of the case that the condition complained of and associated with the Respondent's period of employment, was a condition described as "persistent or constant" tinnitus. Thus, some of the cross-examination of the Respondent, which demonstrated that he had suffered from intermittent tinnitus, at a lower level, prior to his employment with the Appellant, was not treated as fatal to the Respondent's case. The critical passage in his Honour's judgment in this regard is a lengthy sentence, which must be set out in full: "But accepting, as I do, that the plaintiff's condition of tinnitus became persistent or constant during the period of his employment and that during that period he was exposed to a noisy work environment and that the defendant failed to use reasonable means to protect workers including the plaintiff from risk of injury from a noisy work environment, I have come to the conclusion that the persistent or constant tinnitus suffered by the plaintiff during his employment with the defendant was caused as a result of the failure of the defendant to take reasonable measures to protect the plaintiff from foreseeable risk of injury from a noisy work environment." 19 The challenge in this Court to that finding was that, having eschewed any finding of significant hearing loss, his Honour's conclusion as to causation relied on nothing more than a temporal association between an unduly noisy environment and the persistent tinnitus. The challenge with respect to causation 20 The essential challenge by the Appellant had two limbs. The first may be summarised as follows: in accepting the evidence of Mr Eden that "the condition of tinnitus is consistent with noise-induced hearing damage" and that "noise-induced hearing loss is probably the most common cause of debilitating tinnitus", his Honour implicitly accepted, on the balance of probabilities, that the Respondent's tinnitus was caused by the hearing loss, which was not itself attributable to his employment with the Appellant. 21 The second limb was that, to the extent that noise-induced hearing loss was not the cause of the tinnitus, the cause was unknown, in which case his Honour could not have been satisfied that the cause was excessive noise during his employment with the Appellant. 22 These two limbs, taken together are, at least on their face, highly plausible. The question is whether, on a fair reading of his reasons for judgment, these statements accurately reflect the logic of his Honour's conclusion. 23 Reading his Honour's judgment as a whole, including the passages to which the Court was taken in the second part of the judgment, dealing with damages, his Honour's approach may be encapsulated as follows. (a) Mr Hrstic undoubtedly had many years of employment in noisy conditions which led to noise-induced hearing loss. (b) His state of noise-induced hearing loss gave rise to intermittent and relatively mild tinnitus, but rendered him susceptible to persistent or constant tinnitus. (c) Although there is a clear association between noise-induced hearing loss and tinnitus, the nature of the association is unclear and is consistent with a common independent cause, namely excessive noise levels. This is at least consistent with his Honour's understanding of Dr Carroll's view that an increase in tinnitus without any increase in hearing loss was possible. (d) Even if it is unlikely that persistent tinnitus could arise without some level of further impairment of hearing, the difficulty in determining whether there was additional hearing loss arising from the relevant employment means that a further hearing loss may possibly have resulted. (e) The common association between excessive noise levels and tinnitus justifies the conclusion that, on the probabilities, the excessive noise levels caused the tinnitus. (f) The causal connection is not precluded by the absence of evidence establishing an increase in aural impairment, or hearing loss. 24 Accepting that the previous paragraph contains a reasonable paraphrase of his Honour's reasoning, or at least summarises the process of reasoning which I would independently adopt, the question is whether that reasoning is flawed in a manner which would not permit the finding of causation which his Honour made. 25 In approaching the question of causation, one must bear in mind, as the Appellant accepted, the need to adopt a commonsense approach, without making overly nice distinctions based on science or logic: see March v Stramare (E&MH) Pty Ltd (1991) 171 CLR 506 at 509 (Mason CJ) and 530-531 (McHugh J). Nevertheless, such comments have been made, as in the case of March, in circumstances where the physical relationship between the negligent act and the damage suffered was not in doubt. Thus, in March, a motor accident case, it was the negligent parking of one vehicle and the negligent driving of the other, which resulted in a collision. In that context, the difference between the legal concept of causation and that which might be applied by a philosopher or scientist is readily understandable, although a court should heed the warnings of McHugh J at 532 as to the dangers of appeal to a "commonsense notion of what constitutes a 'cause'" as a façade to justify unprincipled or incoherent reasoning to a preferred conclusion. 26 In the course of argument, Counsel for the Appellant called in aid the approach adopted by this Court in Bendix Mintex Pty Ltd v Barnes (1997) 42 NSWLR 307. That was presumably an invocation of the principles stated by Mason P after considering various ways in which the law provides mechanisms to assist plaintiffs faced with multiple defendants, yet uncertain as to which of them was legally responsible. In Bendix, at 318B, the President stated: "But none of these procedural or adjectival concessions in favour of the uncertain plaintiff support the principle that a party who negligently exposes a plaintiff to a risk of injury will be liable unless the plaintiff can persuade the trier of fact that it was probable that the risk came home. The basal principle remains that: 'The law never gives judgment in favour of a plaintiff when the only finding is equally consistent with liability and non-liability.' " 27 Of course, the situation where it is likely that some, but not necessarily all, of a class of defendants were liable must be distinguished from the case where because a material contribution to an injury is sufficient, a case may be made against all. That, as the President noted in an earlier passage at 314-315, explains the passage in the speech of Lord Bridge in Wilsher v Essex Area Health Authority [1988] AC 1074 at 1088 stating: "… where the layman is told by the doctors that the longer the brick dust remains on the body, the greater the risk of dermatitis, although the doctors cannot identify the process of causation scientifically, there seems to be nothing irrational in drawing the inference, as a matter of commonsense, that the consecutive periods which brick dust remained on the body contributed cumulatively to the causation of the dermatitis." 28 In the final analysis, the question of causation in such cases, where science does not provide an explanation as to the link between a putative causative factor and a result, must ultimately be seen as involving a question of satisfaction of the burden of proof. That point is illustrated by numerous authorities, which have helpfully been collected in the judgment of Spigelman CJ in Seltsam Pty Ltd v McGuiness (2000) 49 NSWLR 262 at [80]-[98]. Bearing in mind that it is sufficient to demonstrate that a condition or disability is either caused or materially contributed to by the negligent conduct, the Chief Justice adopted the statement of Glass JA in Fernandez v Tubemakers of Australia Ltd [1975] 2 NSWLR 190 at 197 to the following effect: "The issue of causation involves a question of fact upon which opinion evidence, provided it is expert, is receivable. But a finding of causal connection may be open without any medical evidence at all to support it …, or when the expert evidence does not rise above the opinion that a causal connection is possible… . The evidence will be sufficient if, but only if, the materials offered justify an inference of probable connection. This is the only principle of law. Whether its requirements are met depends upon the evaluation of the evidence." The correctness of that statement is confirmed by the judgments in the High Court on appeal in Tubemakers of Australia Ltd v Fernandez (1976) 50 ALJR 720. 29 Applying those principles in the present case, it was open to the trial judge to be satisfied on the balance of probabilities that the exposure to excessive noise levels in the Appellant's mine contributed materially to the onset of persistent tinnitus. The link between high noise levels and tinnitus was not in question: the only question was whether some physiological condition, associated with aural impairment, was an essential element in the chain of causation. There was no evidence that it was, if only because the evidence demonstrated that the cause of tinnitus is not properly understood. Furthermore, there was evidence (relied upon by the Appellant for different purposes) that tinnitus could be caused or aggravated by stress. The Court was entitled to take that evidence into account in reaching a satisfaction on the balance of probabilities that a demonstrable loss of aural ability was not a prerequisite to finding a causal connection between exposure to noise and persistent tinnitus. 30 For completeness, it is convenient to note that the trial judge made no finding in relation to the defence suggested by the cross-examination, namely that it was the stress of a possible job loss, resulting from the flooding of the mine, rather than exposure to undue noise, which led to the tinnitus. It may be that that was abandoned before final submissions, in part for tactical reasons, the Appellant considering that its largely inconsistent defence that the tinnitus arose prior to the employment had better prospects of success. 31 However, while this particular line of defence was not agitated on the appeal, a similar argument, but at a greater level of generality, was relied upon, namely that because the causes of tinnitus are unknown, tinnitus in the particular case may well have been caused by factors unrelated to the exposure to noise in the Appellant's mine. However, once the anchor to the particular facts of the case is abandoned, the submission is reduced to a question of speculation. There was ample reason for the trial judge to accept that, in the absence of any contrary explanation, and accepting the proposition that high noise levels could be a cause of tinnitus, the causal connection was established. 32 It follows, in my view, that the conclusion of the trial judge with respect to causation should be upheld and the appeal in relation to liability dismissed. Challenge to finding with respect to non-economic loss 33 The second ground of appeal concerned the assessment made by his Honour in relation to non-economic loss. This assessment required the application of s 151G of the Workers Compensation Act, as it stood at the date of injury, which is assumed for this purpose to have been 26 October 1999. The relevant provisions for present purposes, subject to variation of the prescribed amounts, read as follows: " 151G Damages for non-economic loss (2) The amount of damages to be awarded for non-economic loss is to be a proportion, determined according to the severity of the non-economic loss, of the maximum amount which may be awarded. (3) The maximum amount which may be awarded for non-economic loss is $204,000, but the maximum amount may be awarded only in a most extreme case. … (7) Division 6 of Part 3 (indexation of amounts of benefits) applies as if the amounts … were adjustable amounts and were referred to in section 81(1). … (8) If an amount mentioned in this section: (a) is adjusted by the operation of Division 6 of Part 3; or (b) is adjusted by an amendment of this section, the damages awarded are to be assessed by reference to the amount in force at the date of injury." 34 We were advised that the amount specified in sub-sec (3) had been, at the date of injury, adjusted to the amount of $240,350. 35 There is no question that the trial judge understood the nature of the task required by this provision and applied it. His Honour assessed the appropriate proportion as 30% of the maximum amount which may be awarded. 36 Before reaching his conclusion in this respect after a consideration of the severity of the Respondent's condition, the thrust of his Honour's findings may be explained by the following extracts from his judgment. "The plaintiff, I accept, has had a rather severe reaction to the condition of tinnitus. He has been described as a person who has an obsessive nature. On the evidence before this Court he clearly was a person who enjoyed his work in the mining industry and has become frustrated and annoyed at his inability to continue to work in the industry. … The plaintiff for a period of time suffered, on the evidence before me, severe depression, but following psychological and psychiatric treatment he did improve. He considers that the tinnitus is becoming worse and as a result of the problems he had with tinnitus the plaintiff's employment came to an end. … The plaintiff is obviously frustrated at not being able to continue to work in the mining industry and has lost a great deal of enjoyment of life in not being so able." 37 As has been recognized the statutory terminology does not oblige a mechanical exercise in assessing a relevant proportion: it merely requires that the proportion be determined "according to the severity of the non-economic loss": see, in particular Southgate v Waterford (1990) 21 NSWLR 427 at 442; Dell v Dalton (1991) 23 NSWLR 528, 532; and Franklins Ltd v Burns [2005] NSWCA 54, in relation to s 151G specifically at [52]-[55]. The prescribed amount, of which the proportion must be calculated, should be understood as applicable in "a most extreme case" on the scale of severity of non-economic loss. The use of the indefinite article "a" suggests a class of case, rather than a specific example. Furthermore, the very nature of the exercise precludes precise assessment: at the most, one can identify bands or ranges within which a reasonable assessment may be made. 38 As Counsel for the Appellant fairly reminded the Court, a conclusion as to the relevant proportion has effects which are not limited to the assessment of non-economic loss. Thus, once the proportion of the maximum amount falls below approximately 23.5%, no economic loss will be recoverable, even if suffered. The Appellant noted, correctly, that those consequential effects must be treated as irrelevant considerations in determining the amount to be awarded for non-economic loss. It was not suggested in the present case that the trial judge erred by taking such factors into account. Indeed, it is not put that his Honour erred at all in relation to relevant principles to be applied. The only error identified was that the proportion upon which his Honour fixed, namely 30%, was, in effect, not within the appropriate range. 39 Underlying this submission was an assumption, which was not explored in argument. The assumption appears to be that the relevant proportion must be placed on a scale between 0 and 1, (often expressed as a percentage) where 1 is the maximum award and 0 is no award, which would presumably apply where there had been no relevant loss suffered. The section does not state this assumption, but it may reasonably be implied and should therefore be accepted. 40 It may be argued that because the provisions in relation to non-economic loss distinguish carefully between an assessment of non-economic loss at 17.6% (which would exclude all such loss) and an assessment at 23.5% or over (which would permit full recovery of non-economic loss) a reasonable range should be tightly defined, since the statutory 'tail' covers 6%. 41 It is perhaps an irony in these circumstances that the Appellant submitted that a proper assessment should fall within the range 5-10%, a range almost as great as the 'tail' provided for in relation to non-economic loss by the statute. Nevertheless, in my view, such a range would not be too broad, especially for a level of severity which so closely approached the end of the scale associated with insignificant loss. However, that range is not necessarily appropriate in the present case. Where a case does not fall at one extreme of the scale, a wider range may be considered legitimate. In the present case it is not unreasonable to pick a proportion between 20% and 30%. Whether the figure chosen by the trial judge of 30% is near to or at the top of the appropriate range need not be determined: it is, in my view, not outside it. I would not interfere with his Honour's assessment. 42 This approach is intended to be consistent with that adopted by this Court in Rabay v Bristow [2005] NSWCA 199, in which, after considering the particular circumstances of the case, McColl JA (with whom Handley JA and Bryson JA agreed) concluded that the assessment of the proportion adopted by the trial judge was not "unreasonable or plainly unjust" in accordance with the principles to be found in House v The King (1936) 55 CLR 499 at 505. Those, of course, are not the only grounds upon which this Court could intervene: however, where, as in this case, no relevant error of principle has been identified, the Court should not intervene unless the assessment can be so described, or, as reflected in the words of s 106 of the Supreme Court Act, the assessment is "manifestly too high". That is not, in my view, this case. Conclusion 43 For the reasons set out above, I would propose that the appeal be dismissed with costs. 44 BURCHETT AJA: I agree that the orders proposed by Basten JA should be made, for the reasons he has stated. 45 As his Honour has pointed out, the trial judge referred to the period of employment as extending to 24 November 2000. The portion of this period after the onset of tinnitus on or about 26 October 1999 was, of course, not irrelevant. To the extent that the respondent continued to be subjected to the excessive noise which had precipitated his condition, it was reasonable to suppose this continued assault upon his already damaged organs of hearing would have been partly responsible for the ultimate degree of his disability. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.