Yawning is an involuntary reflex characterized by a deep, slow inhalation followed by a brief pause and a rapid exhalation. This motor pattern involves a pronounced stretching of the muscles in the face, neck, and respiratory system. Although the primary function of yawning remains a topic of scientific discussion, the process often produces sounds like a click, pop, hiss, or wheeze. These audible effects result directly from the mechanical forces and rapid air movement occurring within the head and throat during the stretch.
Ear Pressure Changes and the Popping Sound
The most common noise associated with yawning is the sharp click or pop originating deep within the ear. This sound results from a rapid change in air pressure within the middle ear space. The middle ear connects to the back of the throat (nasopharynx) via a narrow channel called the Eustachian tube.
The Eustachian tube is normally collapsed and closed, which helps protect the middle ear from secretions. It must open periodically to balance air pressure on both sides of the eardrum, a process known as ventilation. Yawning is an effective, natural way to force this opening.
The large, downward movement of the jaw and the stretching of the throat muscles during a deep yawn activate the tensor veli palatini muscle. This muscle attaches directly to the cartilaginous wall of the Eustachian tube. When the tensor veli palatini contracts, it pulls the tube walls open.
When the tube opens, air rushes in or out of the middle ear to equalize the pressure with the surrounding atmosphere. This sudden shift in air movement and the snapping open of the tube’s walls create the distinct popping or crackling sound that is heard. This mechanism is the same reason yawning can relieve the sensation of fullness in the ears during altitude changes.
Air Movement Through the Respiratory Tract
Another type of sound often heard during a yawn is a turbulent rush, hiss, or wheeze, which is separate from the ear-popping mechanism. This noise is generated by the large volume of air being inhaled at high speed through the upper respiratory tract. During the deep inhalation phase of a yawn, the pharynx, the muscular tube behind the nose and mouth, widens significantly.
The soft palate, the fleshy, movable part at the back of the roof of the mouth, also stretches and elevates during this process. The rapid movement of air passing over the soft palate and through the newly enlarged pharyngeal space creates a turbulent airflow. This turbulence is the source of the audible rushing or sighing noise.
The overall sound is further influenced by the stretching of the larynx and vocal cords. The prominent downward movement of the larynx and hyoid bone during the deep inspiration of a yawn alters the tension of the vocal folds. This physiological stretching, combined with the rapid, deep inhalation, contributes to the unique, drawn-out sound texture of an audible yawn.
When the Noise Signals a Different Issue
While most sounds produced during a yawn are normal, persistent or painful noises can occasionally indicate an underlying issue. One common source of clicking, often confused with the ear pop, is the temporomandibular joint (TMJ). A wide-open yawn can cause a clicking sound if the small cartilage disc within the joint slips out of alignment.
This TMJ clicking, known as disc displacement, usually occurs in front of the ear and may be accompanied by pain or limited jaw movement. Chronic Eustachian Tube Dysfunction (ETD) is another consideration, where the tube remains blocked due to inflammation from colds or allergies. The yawning sound may then be a painful or muffled pop, often paired with persistent ear fullness or hearing changes.
A rare condition called Patulous Eustachian Tube (PET) can also be signaled by a noise during yawning, where the tube remains abnormally open. This causes a person to hear their own breathing, voice, or pulse loudly, a phenomenon called autophony. If the noises are painful, constant, or accompanied by symptoms like dizziness or muffled hearing, seek professional medical advice.