Final answer:
The round instrument heard in medical contexts is the stethoscope, a device essential for auscultation that transmits body sounds to the eardrum very effectively. It was a significant innovation and is used to concentrate sound onto the eardrum for better diagnosis of heart conditions.
Step-by-step explanation:
The instrument referenced in the question is called a stethoscope. It is a medical device used for auscultation, which is the act of listening to the sounds of the body, typically the heart and lungs. The stethoscope was an important medical innovation in the late nineteenth century. It allows sound to be transmitted more effectively by direct contact with the body and is concentrated on the smaller area of the eardrum. The eardrum then vibrates to these sounds, which the inner ear translates into electrical signals that are sent to the brain for interpretation. The effectiveness of a stethoscope in transmitting sound compared to air can be measured in decibels, and its use is one of the simplest diagnostic techniques to assess a patient's heart.
Sound transmission is more effective with a stethoscope due to the efficient gathering and focus of sound waves onto the eardrum. The three ossicles of the middle ear, known as the malleus, incus, and stapes (also referred to as hammer, anvil, and stirrup), are critical in transmitting these sounds to the cochlea, containing receptors for the transduction of mechanical waves to produce electrical signals.