Review of Understanding Lung Sounds from British Journal of Diseases of the Chest:

“The stethoscope can be, for some, as much a badge of office as a delicate tool for the recognition of normality and abnormality in the lungs. Exquisitely sensitive as it is, it may fail if it is not used, if it is badly used and if the sounds generated are poorly interpreted. Poor use and interpretation can come from those who do not know what to listen for, or how to listen. It can come also, especially in students, from uncertainty of the understanding of the nature and naming of the sounds. So many of Laennec's patients must have suffered severe tuberculosis (as eventually did he himself), bronchitis or pneumonia. To interpret he set out to describe normal and abnormal lung structure from the results of inspection, percussion and auscultation. Little changed from 1818 until the middle of this century. Now, after work by a number of American physicians, but above all, by Dr Paul Forgacs; (Lung Sounds, Bailliere 1978) there has been clarification. Lung sounds can now be interpreted in terms of normal and abnormal lung function. A simpler description and better interpretation of lung sounds can, therefore, be given.

Steven Lehrer has written descriptions of lung structure, of lung sounds, of hearing and the stethoscope and of the history and physical examination of the patient with chest disease. He gives a description of breath sounds, normal and abnormal: this with a short history of previous beliefs. This account of the nature and generation of normal and abnormal lung sounds is the best so far published. Recent investigations of lung sounds are summarized.

The description of the clinical examination of the lungs is as good as any so far. The description of the nature of the lung sounds is better than any so far. The illustrations are many and informatively linked to the text. The sensibly simpler British system of naming the adventitious lung sounds is preferred to the slightly more complicated American ones. Usefully, a sound tape is included with the book. So long as the user of it knows that the tape can not identically match what he or she hears, and could not do so, the tape will help students using the stethoscope recognize the nature of order and disorder in the lung sounds made by their patients, and heard on auscultation.

Any criticism of minor features of this good book would be but minor quibbles. It is a superb introduction into the understanding of the lung and its sounds. All students should have it. All GPs and physicians, especially chest physicians, should find it greatly informative and should perhaps get it. A very old subject (in the past, sometimes a subject of passionate argument) beautifully made a new one, like so much that is better in medicine.

L.H. Capel
British Journal of Diseases of the Chest
VOL. 80: 203-204, 1985.   pdf

Review of Understanding Lung Sounds 2nd edition from Chest:

“Understanding Lung Sounds is a paperback with accompanying audiotape that provides an introduction to the art of auscultation of lung sounds and physical diagnosis of chest diseases. The book affords a written explanation of the mechanics of respiratory findings and couples it with the schematic representation of sophisticated lung sound analysis. The audiotape provides examples of the described auscultatory findings.

In this edition, Dr. Lehrer covers both normal and abnormal lung sounds, which allows the novice a unique experience in physical diagnosis of the chest. His text is concise and very understandable for the medical student, nursing student, or physician. The accompanying tape is of excellent quality and provides findings that would be hard to assemble at one time, if patients were required. This variety of findings allows the listener, for instance, to compare and distinguish normal from abnormal and low pitched crackles from high pitched crackles.

This text would be a good addition to any medical student's library. As a teacher of Physical Diagnosis, this reviewer also found it to be a highly recommendable adjunct text for the course. Although a bit simplistic for the experienced practitioner, it is well written. This text is an excellent introduction to understanding lung sounds through sight and sound.

Tim Ferguson, MD
Evansville, Indiana
Chest 1995; 107:20

Understanding Lung Sounds, by Steven Lehrer, 2nd ed, 150 pp. with Illus, paper, and 1 audiocassette, $35.95 ISBN 0-7216-4902-5, Philadelphia, Pa, WB Saunders Cc, 1993.

Steven Lehrer's introduction to auscultation is a primer of pulmonary diagnosis using lung sounds as its unifying theme. Intended to educate the ear as much as the mind, his kit is a self-contained learning experience for the medical student. It may also be useful for critical care and pulmonary service nurses. The kit is an excellent learning system and is highly recommended as an introduction to the topic.

The book begins with an homage by Victor McKusick to the Golden Age of auscultation, introduced by Rene Theophile Hyacinthe Laennec in 1816. The sketch is too brief to elaborate on the fascinating history of auscultation, which at the time was a monumental undertaking. Laennec codified his work in 1819 in his book Traité de l'auscultation médiate, an effort that exhausted him and extracted a two-year period of recovery from his career. Laennec was a pupil of Jean Nicholas Corvisart, the leading advocate and systematizer of chest percussion. Mentor and student defined the chest examination as we know it. Lehrer continues the work, as the transmitter of a grand tradition.

The first chapter reviews the anatomy of the lung and the physiology of ventilation, omitting blood gas interpretation. Lehrer also introduces common pathological conditions, briefly exploring their auscultatory findings. The second chapter shifts attention to the other end of the stethoscope: the listener. Lehrer discusses sound characteristics, the hearing mechanism, and the stethoscope as an instrument. In the third chapter, he introduces the history and physical examination of the patient with chest disease. Here he departs from the emphasis on auscultation to provide the student with a context for the auscultatory examination--an appreciation for the findings that are likely to accompany the abnormal sounds.

Chapter 4 discusses normal breath sounds. This is a fine outline of physical examination of the chest, worth a complete physical diagnosis teaching session with students. It also introduces a simple graphic system of notation. The interested specialist may welcome the discussion of recording systems and waveform analysis. The novice may find this tedious, but the visual display of a waveform does help to prepare one for informed listening. Chapter 5 is what most students will consider the meat of the program, an outstanding and comprehensive treatment of abnormal lung sounds that does not ignore minor phenomena such as mouth noises. Mixing clinical observation with experimental findings, Lehrer explains the origins of abnormal lung sounds and interprets them in keeping with structural and functional changes in the lung. The script to the accompanying tape, a glossary, and an index round out the book.

The script and tape provide examples of the more important normal and abnormal lung sounds, followed by a short quiz. Each lung sound is introduced, demonstrated, and explained. Lehrer has the student listen to the tape through a stethoscope to ensure realism.

For the more experienced reader, the text reminds one how unsatisfactory the usual descriptors of lung sounds have become. After Laennec's elegant system in French, his English-speaking disciples (who are legion) seemed determined to add their own vocabulary. Both the American Thoracic Society and the American College of Chest Physicians have tried to standardize the terminology, in so doing unfortunately reducing it to an impoverished few words: rales (or crackles), wheeze, and rhonchus. Lehrer is wise to use British descriptors, which are more precise. However, there is something evocative about terms like "consonating rales," and one misses the poetry of authors like J. Milner Fothergill, who wrote in his Chronic Bronchitis (New York, NY: GP Putnam's Sons; 1882: pp.23-24): "Careful percussion . . . tells much about the complications of chronic bronchitis; even when it has nothing to say about the malady itself. Auscultation, however, is eloquent, even loquacious, about the disease.... Sometimes, especially when the patient is asleep, there may be quite a musical note...."

Medical texts will never be written like that again, but Lehrer's prose is as clear and precise as Fothergill's and on occasion even gets mildly carried away with the romance of its subject.

Tee L. Guidotti, MD, MPH University of Alberta Edmonton
JAMA 1995; 273(12):971 pdf

“How long has it been since you have heard bronchial breath sounds over the chest of a patient with pneumonia? How long since you have heard amphoric breath sounds, late inspiratory crackles, monophonic wheezes, inspiratory and expiratory squawks, and egobronchophony? Well, here is your chance to hear them. Steven Lehrer's cassette tape has these as well as a lot of the other sounds that sick lungs make. And if for some mysterious acoustical reasons, best known to himself, Dr Lehrer recommends listening to the tape through a stethoscope while holding its bell 2 to 3 inches from the speaker of the tape player, I shall not gainsay him.

Accompanying his cassette tape, Dr Lehrer's paperback gives a bird's eye view of contemporary pulmonology. He discusses, for example, both normal and abnormal breath sounds. Turbulent air flow in lobar and segmental bronchi produce the normal breath sounds. In the alveoli, he writes, air flow is soundless, since it is slower and not nearly so turbulent. He takes up, however briefly, techniques of history taking and physical examination. Among the book's many illustrations, he even includes a picture of the human ear in cross section as well as graphic details of the Heimlich maneuver. I found his book concise, readable, and interesting.

The diseased lung, he writes, generates many distinctive sounds such as crackles, wheezes, and pleural friction rubs. On the other hand, abnormalities of sound transmission can also lead to interesting findings such as pectoriloquy, bronchophony, and others. He describes crackles as short, explosive, nonmusical sounds and classifies them by their position in the respiratory cycle. Early inspiratory crackles are characteristic of severe airway obstruction and seem to be produced in proximal and larger airways. Late inspiratory crackles seem to originate in peripheral airways and may occasionally be associated with a late inspiratory wheeze. Late inspiratory crackles are characteristic of restrictive pulmonary disease and may be heard in patients with interstitial fibrosis, pneumonia, and pulmonary congestion.

It is Dr Lehrer's remarkable cassette tape that mostly attracts me, however. By what acoustical process he got these and many, many more abnormal lung sounds onto his tape, I cannot even guess. I can write only that I found listening to his tape easy. The sounds were clear and readily identified. I did not have to strain my ears or my imagination. In short, Understanding Lung Sounds is here for the listening and can be, and I predict will be, enjoyed by all who take the trouble to listen.

Harry B.Greenberg
JAMA 1985; 253:2585

Review of Understanding Lung Sounds from Annals of Internal Medicine:

OUR STUDY of the genesis and significance of normal and abnormal lung sounds dates from the time of Laennec, but our understanding has grown greatly over the last 2 decades with the advent of the modem techniques of acoustic analysis of breath sounds. Lehrer includes discussions on the physics of sound and the use of sound spectrography as an introduction to a comprehensive description of the techniques of physical examination of the thorax, with special attention, of course, to auscultatory phenomena. The exposition is clear, accurate, and state of the art.

The audiocassette presents high quality recordings of normal and abnormal auscultatory signs, with accompanying verbal descriptions that are detailed enough that the cassette would be instructive if used separately, without the text. The cassette even includes an example of a bronchial "leak squeak."

The book and cassette are ideal for courses in physical diagnosis, and the astonishingly low price undoubtedly enhances their appeal. These materials can be studied with profit by all physicians who use chest stethoscopy, and particularly by those who do not use it but should. The content is timely but relatively timeless; it will not soon go out of date.

Glen A. Lillington, M.D.
University of California, Davis
Sacramento, California
Annals of Internal Medicine 1985; 103:885.

Understanding Lung Sounds. Steven Lehrer. (Pp 144; 88 illustrations; cassette tape; W B Saunders. 1984)

The terminology of lung sounds has produced disagreement since Laennec's original publications in the early nineteenth century. Laennec, who meticulously recorded his descriptions of lung sounds with phrases such as "a gnat buzzing within a porcelain vase," proposed that all the added sounds heard through the stethoscope be called rales. The association of the term rales with the noise of sputum retention in the large airways of dying patients, the death rattle, led to the alternative term, rhonchus. Problems with translation and application of these terms, together with the subdivision of rales into moist, mucous, sonorous, sibilant, and dry or crackling, all helped to produce confusion. Laennec's other work on normal and abnormal breath sounds and voice sounds still stands more or less unchanged after more than 160 years.

The terminology remained confused until Paul Forgacs tried to clarify it in the 1960s. He suggested limiting the terms for added sounds to wheezes and crackles. This sensible suggestion was almost adopted by the American Thoracic Society recommendations of 1980, although they unfortunately retained the term rhonchus as well as wheeze. Many of the British and American textbooks on techniques of physical examination in the past 10 years have failed to take up this sensible simple terminology, or to take account of the work on the derivation of the sounds. Publications in 1984 still describe crackles as deriving from air bubbling though fluid filled alveoli.

In this package Steven Lehrer has produced a book and a cassette designed mainly to teach how to listen to breath sounds. The ideas on the generation of lung sounds rely heavily on the work of Forgacs, Nath, and Capel, and Lehrer has used the crackle and wheeze terminology. The book has an initial chapter on anatomy, physiology, and pathology, which seems inappropriately simple. The following chapters on the stethoscope, history and examination, and normal and abnormal breath sounds are much more useful. The final chapter reproduces the text of the accompanying tape. Many of the illustrations in the handbook are taken from other publications.

A cassette is the obvious medium to teach the modern medical student about sounds that are difficult to describe. Many students have benefited far more from listening to tapes of heart sounds produced by Medi-Cine and ICI than from imagining third and fourth heart sounds are imitated by peculiarly pronounced American states. The film on lung sounds produced some years ago by Nath and Capel still provides an excellent introduction to the subject, but a cassette tape allows the student to repeat the sounds as he or she likes.

The reproduction of this tape is good, and I was convinced that this was best heard by listening through a stethoscope, avoiding the Fletcher-Munson phenomenon which is described in chapter 2. The second side of the tape allows a brief testing on some of the sounds heard on side 1. A few of the sounds described may be less familiar, particularly the inspiratory squawk and the bronchial leak squeak, which proved so acutely disturbing to my cat quietly dozing nearby. The derivation of expiratory crackles is not really dealt with, and that great favourite of many chest physicians, pendelluft, is not mentioned.

Overall, this is an excellent introduction to the auscultation of lung sounds and all medical students would benefit from listening to this tape at the start of their clinical work. The price is expensive, and perhaps it might have been kept down with a simpler accompanying booklet. Nevertheless, with this new introduction there is now the opportunity to have read the book (Forgacs), seen the movie (Nath and Capel), and listened to the cassette. Fortunately, in the end, there is no real substitute for listening to the patient.

John Rees
British Medical Journal 289:824-825, 29 September 1984

Review of Understanding Lung Sounds 2nd edition from The Lancet

This second edition is updated to include information about computer­aided analysis of lung sounds. The technique, known as time-expanded wave-form analysis, employs a computer with analogue digital conversion to record lung sounds which can then be replayed at a much slower rate and displayed in graphical form. This allows detailed analysis of the wave form. It is also possible to carry out spectral analysis of the frequencies that make up each lung sound. The basics of this technique are described and some graphical displays are included to illuminate the discussion. However, the account of the methods and applications of computer-assisted analysis of lung sounds is too brief and superficial for the book to be of much interest to a respiratory specialist.

Understanding Lung Sounds is most suitable for medical students. There is a useful introduction to aspects of the physics of sound that are necessary to understand lung sounds, and a good description of normal and abnormal sounds. An innovative feature of the book is the provision of a cassette tape of normal and abnormal lung sounds, which is a useful introduction for the novice. Limitations in reproduction are overcome to some extent by following the author's advice to listen to the tape through a stethoscope held some distance away from the sound system speakers.

Much of the book is not directly concerned with lung sounds. Sections on anatomy, physical examination, and diagnostic methods in respiratory medicine are useful for students, but are better covered elsewhere. It is difficult to see the relevance of some of the illustrations such as dramatic diagrams of the Heimlich maneuver in infants and adults.

The book will be a worthwhile addition to libraries for medical students and junior doctors, but there is not enough here to satisfy the specialist respiratory physician.

R M Rudd
London Chest Hospital, London E2 9A, UK
The Lancet 1993; 342:1225 pdf

The sections on lung sounds are on the whole well done and include a lot of up-to-date information...A strong feature of this book is the illustrations. They have been well chosen and come from a variety of sources. They illustrate many aspects of the subject in helpful and relevant fashion...The lung sounds on the accompanying tape are of good quality...

New England Journal of Medicine 1984; 311:1389