The significance of sound: Learning through listening

Sound is, in essence, oscillation in pressure, stress, particle displacement or particle velocity propagated in a medium with internal forces, or superposition of such propagated oscillation. Auditory sensations are evoked by this oscillation. Sound has many properties, one being frequency. Humans can hear sound with a frequency of between 20 Hz and 20 kHz. ‘Ultrasounds’ are sounds above normal hearing; most medical diagnostic ultrasounds have a frequency above 2 MHz.

Auscultation of the chest has been performed since the days of Hippocrates. Many modern-day physicians still believe that they can hear ‘air entry’ into the alveoli of the lung. Breath sounds are actually not caused by air entering the alveoli (as diffusion is silent), but by turbulent flow in large airways that are poorly conducted by aerated lung tissue.

Transthoracic ultrasound (TUS) was for many years underappreciated as an imaging tool. I investigated the feasibility of TUS-assisted biopsies performed in various settings, and consistently found acceptable to very high diagnostic yields with minimal complications. Furthermore, I was able to validate a novel indication for TUS-assisted fine needle aspiration (drowned lung), validate the use of a single-session sequential approach in at least two clinical settings (superior vena cava syndrome and anterosuperior mediastinal masses) and also found that TUS-assisted Abrams needle biopsy was superior to Tru-Cut needle biopsy when histological confirmation of TB pleuritis was required.

Learning through listening does not end here. I have acquired a vast amount of scientific knowledge and learned many life lessons purely by listening to people wiser than me. The most important lesson, thus far, was “Just do it!”

Short biography

Coenie Koegelenberg was born in Cape Town and matriculated as Stellenberg High School’s dux scholar in 1989. He completed his MBChB (cum laude) in 1995 at Stellenbosch University and was awarded the gold medal as the best final-year medical student. After completing his training in general internal medicine in 2001 at the same university, and passing his MMed (Int) cum laude and his FCP (SA) examinations, he spent 30 months working in the United Kingdom, where he also qualified as a specialist. He returned to South Africa to complete his training in pulmonology, and was appointed as a consultant in respiratory and critical care medicine at Tygerberg Hospital in 2005. He was appointed as an associate professor in pulmonology in 2012 after completing his PhD, and promoted to professor in 2017.

Coenie is primarily a clinician who is involved with, among other things, the teaching of ultrasound skills to fellow clinicians.

His research interests over the past decade have included lung cancer, infectious and pleural diseases, preoperative assessment and more recently applied transthoracic ultrasound and interventional pulmonology. Coenie is the author of more than 130 peer-reviewed papers and 15 textbook chapters, most on transthoracic ultrasound and infectious and pleural diseases. He has been an invited speaker to many national and international congresses.

Coenie is a fellow of the Royal College of Medicine (London). He is president-elect of the South African Thoracic Society (SATS) and serves as the SATS representative at the World Association of Bronchology and Interventional Pulmonology.