Discussion

In his original work, Laennec used the terms ‘rale’ and ‘rhonchus’ interchangeably, to denote all classes of adventitious sounds.1 Successive translations—first into English and then into other languages—and redefinitions of the original terminology gave different meanings to these terms, starting a confusion that persists to this day. To overcome this drawback, recommendations for use of a standardised terminology in the English language were made by the ad hoc committees of scientific societies.3–5 The recommended terms—simple and precise—are based on the physics of the sounds, without assumptions about their mechanism of generation or site of production.3–5 In a population of caregivers working in Israel, we compared the Hebrew terms used to classify five common sounds with (a) the recommended terminology in English and (b) the terms used by the same caregivers to classify the same sounds in the English language.

In similarity with our companion study,11 the observers’ ability to classify the sounds in Hebrew was high for the wheezes and the stridor, fair for the crackles and low for the normal breath sounds and the pleural friction rub, with the three groups of caregivers performing similarly in classifying all sounds. Even though the SPs performed better than the other groups in classifying the pleural friction rub, the overall performance of the three groups was too low to be considered clinically meaningful. This similarity of performance regarding the two languages is interesting, because, in theory, one could expect the caregivers to perform better in their working language—Hebrew—than in English.

Of three correct Hebrew terms used to classify sound file number 1, just one corresponded to the recommended term ‘normal breath sound’ in English. The other two, ‘vesiculari’ and ‘buyit’—meaning, respectively, ‘vesicular’ and ‘alveolar’, are deemed inappropriate as they convey the incorrect assumption that the normal sound originates from the entrance of air into and out of the air cells of the lungs.1 As a quick aside, although the exact locale and mode of production of the normal breath sound have not been established, there is evidence to support the view that it has a double origin: the lobar and segmental airways for the inspiratory component and a more central source for the expiratory component.12 13

Consistent with our previous study,11 all observers used the classic Hebrew term ‘tziftzufim’ to classify the wheezes. This homogeneous description is interesting. Indeed, the term ‘wheezing’ has been in use long before Laennec’s invention of the stethoscope, while ‘wheeze’, as used nowadays, corresponds to the ‘rale sibilant sec’ described by Laennec.14 We speculate that the traditional attribution of this sound to a single mechanism—airway obstruction—might have contributed for the use of a single term to describe it. Consequently, the translation from the source language (ie, English) to other languages was kept relatively uniform, as found in the present study.

The term ‘stridor’—from the Latin stridere (harsh, shrill or creaking noise)—describes the high-pitched, musical sound produced by turbulent flow passing through a narrowed segment of the upper respiratory tract.15 In similarity with the classification of the wheezes, all correct raters used a single term. However, instead of the Hebrew term ‘שִׁרְנוּק’ (‘shirnuk’), they used the term ‘stridor’ itself, spelled in the Hebrew alphabet. This peculiar choice suggests that, rather than searching for a suitable terminology, the caregivers preferred a term familiar to them. This finding is similar to that reported in a recent survey of lung sound nomenclature carried out in 34 European countries, which showed that caregivers from all the countries—representing 29 languages of which five had non-Latin alphabets—spelled the term ‘stridor’ verbatim in all languages but Greek.16

With two categories—‘fine’ and ‘coarse’—crackles can be defined as brief, non-musical, explosive, adventitious sounds.17 18 In this study, the Hebrew equivalent of ‘crackles’ was used just once, by a MS. Of the other acceptable terms, ‘crepitatziot’ is solely an adaptation of ‘crepitations’, while ‘hirhurim’ is the classical Hebrew term for ‘rales’. It should be noted that both these terms are considered superfluous or inadequate: ‘crepitations’ because it merely means high-pitched crackling and ‘rales’ because, as stated above, it was originally a generic term applied to every variety of adventitious pulmonary sound.1 Incidentally, the accepted mechanism of production of fine crackles is not the presence of secretions in the airways, but the sudden opening of airways in deflated territories of the lung as observed in restrictive lung disorders (eg, interstitial lung disease).17–19

Of the presented sounds, the pleural friction rub is probably the less well studied. Purportedly, it is produced by the sudden release of tangential tension in a superficial portion of the lung momentarily arrested in its sliding movement by a frictional force between the two pleurae.18 The tiny group of observers who correctly classified this sound used two terms (vs four terms in the English part of the survey11): pleural and friction, alone or in combination.

A novel information provided by this study is that poor skills in chest auscultation largely surpassed deficient language skills as a cause of incorrect lung sound classification. Of 90% of participants found to have good language skills, 50% had poor auscultation skills. Consistent with our previous study,11 this finding further illustrates the fact that the use of recommended terminology is meaningful only among observers with good auscultation skills. In fact, observer agreement on a wrong classification can be detrimental to the patients, as it may lead to unnecessary and expensive investigations as well as improper treatment.11

Most of our SPs practised medicine in both Hebrew and English. This aspect has clinical relevance. The ability of non-native English-speaking doctors to communicate with patients in English is now considered a core competency. Consistent with its status of global lingua franca, the English language is the universal means of communication between people with different native languages. In this context, ensuring the similarity of terminology between English and a LOTE is important, as language-concordant healthcare contributes to prevent expensive tests and poor patient follow-up.

To our knowledge, there is no research similar to this study that can provide data for comparison. Searching the literature, we found that the importance of the correct understanding of the original English terminology by caregivers working in a LOTE has been examined only peripherally. For instance, in a survey of seven European countries, lack of familiarity with the English nomenclature was invoked to explain the lower agreement of Russian and Dutch practitioners to classify crackles and wheezes from video recordings.20 Also, in the European terminology survey quoted above, the terms used across the countries were generally non-uniform, some countries having their own terminology and others simply adopting the English terminology.16

This study has limitations. First, for the sake of feasibility, we recruited caregivers from the same hospital, which may limit the generalisability of the findings. However, compensation was provided by their heterogeneity in terms of clinical and educational background. Second, we did not investigate all adventitious sounds. For simplicity, we stuck to the the most common ones, intentionally excluding more complex sounds such as the rhonchus or the squawk, whose inclusion might have further hampered the observers’ ability to classify the sounds. Finally, the experimental conditions were not representative of those in clinical practice. The study design prevented the participants to auscultate all over the chest, at will, or to command the respiratory manoeuvres, which may have altered outcomes compared with real life. However, to avoid more detrimental biases, we were forced to standardise the study conditions across participants.