The experience of perceiving sounds like bells when no external source exists is known as a phantom auditory perception. This phenomenon is common across all age groups, ranging from a simple, fleeting sound to a persistent, complex noise. Understanding this perception involves exploring various medical and neurological pathways.
Understanding Tinnitus and Auditory Hallucinations
The sound of bells can be classified into two distinct medical categories of phantom noise, depending on its complexity. Tinnitus is the perception of simple sounds, typically described as a ringing, buzzing, hissing, roaring, or a simple, steady tone like a single bell. This sound is usually constant or intermittent but lacks any organized pattern.
Auditory Hallucinations (AH) involve hearing more complex, organized sounds, which might include music, singing, voices, or a complicated, repeating series of chimes or bells. When these complex sounds occur alongside hearing loss, the condition is often referred to as Musical Ear Syndrome. The complexity and consistency of the sound help medical professionals determine the category, as the underlying causes can differ.
Complex auditory phantom sounds, such as a full melody of bells, often arise from the brain attempting to compensate for sensory deprivation caused by hearing loss. Unlike hallucinations linked to psychiatric conditions, these auditory experiences are usually recognized by the individual as unreal. Both tinnitus and complex auditory hallucinations involve the brain generating sound in the absence of external input, often as a response to reduced stimulation.
Physiological Causes Linked to Hearing Health
The most frequent cause for hearing phantom sounds is damage to the delicate hair cells within the cochlea of the inner ear, leading to hearing loss. When these sensory cells are damaged, they no longer send expected signals to the brain’s auditory processing centers. The brain attempts to compensate for this lack of input by increasing its sensitivity, which results in the perception of a phantom sound.
Acoustic trauma from prolonged or intense noise exposure is a common mechanism for inner ear damage. Exposure to sounds exceeding 85 decibels, such as from machinery or loud music, can physically harm the hair cells, leading to noise-induced hearing loss and subsequent phantom noise generation. This process can occur gradually over time or suddenly following a single, extremely loud event.
Physical obstructions in the outer or middle ear can also induce the perception of sound. A significant buildup of earwax (cerumen) can press directly against the eardrum, causing irritation or altering its pressure, which the brain interprets as sound. This blockage also muffles external sounds, making any existing internal body noises, including the phantom sound, much more noticeable.
A less common physiological cause is pulsatile tinnitus, a rhythmic whooshing or throbbing sound that synchronizes with the heartbeat. This is often caused by turbulent blood flow in arteries and veins located near the ear. Conditions like high blood pressure, atherosclerosis, or vascular irregularities near the inner ear can create this audible sound.
Systemic and Psychological Contributors
Beyond direct damage to the auditory system, phantom sounds can be triggered or worsened by factors affecting the entire body or the nervous system. Certain medications are known to be ototoxic, meaning they can chemically damage the inner ear’s sensory cells or the auditory nerve. High-dose aspirin, certain non-steroidal anti-inflammatory drugs (NSAIDs), some antibiotics, and specific chemotherapy agents may induce or exacerbate phantom sounds.
Stress and anxiety play a significant role in how intensely a person perceives phantom sounds. The limbic system, the brain’s emotional processing center, is closely connected to the auditory pathways. When a person is highly stressed, the limbic system can tag the phantom sound as a threat, increasing the emotional reaction and focus on the noise, making it seem louder and more bothersome.
Neurological events and physical trauma to the head or neck can also be direct contributors. Head injuries, concussions, or whiplash can cause somatosensory tinnitus, resulting from damage to nerves or altered muscle tension in the head and neck area. Changes in the temporomandibular joint (TMJ) or the cervical spine can also affect the auditory pathway, leading to a phantom sound modulated by jaw or neck movement.
Seeking Diagnosis and Management Options
It is advisable to consult a healthcare provider, such as an audiologist or an otolaryngologist, if the phantom sound is persistent, significantly affects daily life, or is accompanied by other symptoms. Sudden onset, a sound only heard in one ear (unilateral), or the presence of dizziness or vertigo are specific signs that warrant a prompt medical evaluation. The diagnostic process typically begins with a comprehensive hearing evaluation to check for underlying hearing loss, as this is the most frequent co-occurring factor.
Depending on the nature of the sound, particularly if it is unilateral or pulsatile, the physician may recommend further testing, such as blood work or imaging studies like an MRI. Identifying and treating any underlying physical cause, such as removing impacted earwax or managing high blood pressure, can sometimes resolve the symptom entirely. For most cases where a specific medical cause is not correctable, management focuses on reducing the awareness and impact of the sound.
Sound therapy, which uses external noise like white noise or nature sounds to mask or distract from the phantom sound, is a common technique. Hearing aids can be beneficial even for mild hearing loss, as they amplify external sounds and help the brain receive necessary auditory stimulation, often reducing the perception of the phantom sound. Cognitive Behavioral Therapy (CBT) is an effective approach that helps individuals change their emotional response to the sound, promoting habituation so the brain eventually filters the sound into the background.