Protect & Improve Your Hearing & Brain Health | Dr. Konstantina Stankovic

Exploring the complexities of the human auditory system, researchers discuss its astonishing capabilities, from the delicate sensory cells akin to those in fish, to the brain's intricate processing of sounds.

Intricate Structure and Function of Inner Ear

Konstantina Stankovic emphasizes the significant sensitivity of the inner ear's sensory hair cells, which can detect displacements as small as the diameter of a hydrogen atom—an astonishing sub-angstrom level of precision. To illustrate, Stankovic notes that a violinist's minute finger movement, invisible to the eye, can alter pitch, a change readily perceived by the ear. Zacoustic hair cells move at audio frequencies up to 20,000 hertz, underscoring their role in sound detection. The process of hearing begins as sounds move the tympanic membrane, which in turn connects to hearing bones and causes vibrations within the tuned inner ear, where high frequencies are encoded at the base.

The Auditory and Vestibular Systems Are Closely Linked

Stankovic highlights the close connection between the auditory and vestibular systems. The cells within these systems, though they look similar, differ in that they detect vibration at varying frequencies, with the vestibular system responding to lower frequencies. External factors like living near windmills can affect the vestibular system. The inner ear is functional before birth, evidenced by a fetus’s ability to hear the mother's voice. This ear comprises one organ for hearing and five for balance, detecting linear and angular accelerations. Stankovic describes a condition, superior semicircular canal dehiscence, which can result in heightened hearing and vestibular symptoms. This phenomenon wa ...

Hearing loss, a significant condition affecting global health, is broadly categorized into two types: conductive hearing loss and sensorineural hearing loss, each with distinct origins and implications.

Conductive vs. Sensorineural Hearing Loss

Conductive Affects Sound; Sensorineural Originates in the Inner Ear

Conductive hearing loss impedes sound on its way to the inner ear and may arise from various problems such as a hole in the eardrum or fluid behind the eardrum. Such issues can stem from disease processes that freeze the tiny hearing bones.

Sensorineural hearing loss, on the other hand, originates from the inner ear or auditory nerve and is the more prevalent type. This form of hearing loss is especially difficult to study and treat due to the inner ear's minute size, its dense bone encasement, and deep placement at the skull's base.

Factors That Contribute To Hearing Loss

Causes Of Hearing Damage: Noise, Medications, Age, Genetics

The factors contributing to hearing loss are multifaceted, with both environmental and genetic components at play. Environmental factors include noise trauma from loud environments such as concerts, aging, and infections. Noise exposure can lead to conditions like "hidden hearing loss," which presents as difficulty hearing in noisy surroundings or tinnitus, even though standard audiometric testing may not detect it. This condition often affects the synapses between sensory cells and neurons, the hair cells, or neurons themselves.

Infections from various viruses, not limited to the herpes family, can contribute to hearing loss, with some even linking to cancers that can impact hearing. Immunologic factors arise in conditions such as celiac disease or rheumatoid arthritis, which can damage the middle and inner ear without direct infection.

Genetics play a role, with over 200 known genes causing hearing loss. Individuals differ in their susceptibility to noise-induced hearing loss, which may be due to "tough" or "tender" ears, suggesting a genetic predisposition. Studies are uncovering multiple genes connected to this vulnerability.

Children and young animals show an increased sensitivity to noise, indicating a stronger susceptibility to its effects. Women generally have better hearing pre-menopause, but those advantages often equalize post-menopause, suggesting hormonal influences.

Cultural and occupational exposures can a ...

The connection between hearing loss and mental wellness is becoming increasingly evident with ongoing research revealing intricate links to cognitive decline and emotional health challenges.

The Link Between Hearing Impairment and Dementia

Hearing Loss Linked To Cognitive Decline and Dementia Risk

Stankovic and Huberman discuss the established but complex relationship between hearing loss and cognitive health. Although not everyone with hearing loss will develop dementia, identifying individuals at risk is a current goal in the field.

Huberman notes that even mild hearing deficits can cause focus issues and cognitive impairment, and more severe hearing loss is directly related to an increased risk of dementia. Stankovic indicates that hearing loss may accompany a reduced dynamic range of hearing, hindering auditory processing quality, which might relate to cognitive health.

Stankovic also points out that hearing loss often accompanies a reduction in the dynamic range of hearing, where only louder sounds can be perceived, while very loud sounds can become painful, suggesting a potential link to cognitive ability deterioration. The reduction in cognitive speed and aspects related to age-related dementia are noted to often correlate with hearing loss.

The Social and Emotional Consequences Of Hearing Difficulties

Hearing Loss Can Cause Isolation, Depression, and Mental Health Challenges

The social consequences of hearing loss are profound. Stankovic explains that hearing loss can lead to isolation due to misunderstandings in communication and withdrawal from social interaction. Moreover, hearing significantly affects emotional and relational well-being.

Keller's assertion that deafness separates individuals from others emphasizes the social dimension of hearing, highlighting the importance of the sense in maintaining relationships. Stankovic elaborates on how the brain's handling of auditory inputs is critical for emotional well-being, with the auditory pathways closely linked to the brain's emotional pathways, including the limbic system. She gives tinnitus and hyperacusis as examples of auditory issues that can have varied emotional impacts on individuals.

The discussion points out that the inability to apprehend speech in noisy environments can exacerbate social isolation, thus opening the path to potential emotional and mental health problems. Additionally, the cost of unaddressed hearing loss is nearly a trillion dollars annually, attesting to the socio-economic and health detriments of delayed or absent intervention.

There's a difference in how people cope with hearing impairment; while some adapt, others are devastated and struggle to function. The integration of sensory inputs is noted to be influential, with a heavy reliance on on ...

Andrew Huberman and Konstantina Stankovic share insights on strategies for maintaining hearing health, recognizing the subtleties of hearing damage and the essential steps to safeguard auditory function.

The Role of Noise Reduction and Acoustic Environment

Safeguard Hearing: Limit Noise, Use Protection, Control Levels

Huberman suggests the need to take actions such as limiting noise exposure, using protection, and controlling volume levels to protect one's hearing. Stankovic emphasizes the importance of understanding decibel levels and their potential harm, noting that 80 decibels is generally safe for eight hours, but safe exposure time halves with every 3-decibel increase. They recommend taking precautionary measures at loud events, like music concerts, where lower volumes could actually be more enjoyable.

Wearing earplugs is advised to protect hearing at loud events, with several types providing 10 to 30 decibels of sound reduction. At a concert with 120 decibels, earplugs providing at least 30 decibels of reduction should be used. The effectiveness of earplugs depends on their fitting and the correct application to provide the necessary level of protection. Stankovic and Huberman touch on the importance of earplug use in understanding that even sub-threshold sounds can compound over time to create significant harm.

Stankovic discusses sound pollution's impact on wildlife, while Huberman makes a parallel between sensory-induced damage to the nervous system from noise exposure and chemical toxicity, emphasizing the serious consequences of auditory damage.

Huberman discusses the beneficial use of earplugs to improve sleep quality by reducing disturbances. He cites a study showing that people can still process sounds in their sleep and shares his own experience with using wax earplugs to cancel out the sound of his heartbeat.

Lastly, Huberman vows to be more thoughtful about his headphone volume and to reduce noise pollution in his environment, realizing the importance of hearing in life experiences. He advises speaking more slowly and eliminating background noise when conversing with someone who has difficulty hearing.

The Potential Benefits of Dietary Supplements

Huberman and Stankovic discuss the potential protective effects of magnesium for hearing health. Studies demonstrate that magnesium may protect against noise-induced hearing loss, with military personnel benefiting from reduced hearing damage after taking the mineral. In the cochlea, magnesium levels shift notably following noise trauma, making it a focus for preserving hearing. They also note that populations with higher magnesium intake have better hearing.

Magnesium comes in various forms, and magnesium threonate, in particular, is no ...

In the field of auditory health, Stankovic, Huberman, and their colleagues discuss advances in our understanding of hearing mechanisms and the potential of new technologies like cochlear implants, as well as the personalized management of tinnitus.

Advances In Understanding the Molecular Mechanisms Of Hearing

Stankovic reflects on the work of Von Bekesy and the discovery of the endocochlear potential, which contributes to the inner ear's sensitivity by driving ionic current through sensory cells. She also elaborates on the auditory system's sensitivity and redundancy, where multiple nerve fibers are connected to a single hair cell, showcasing the complexity and efficiency of our hearing system.

Stankovic refers to Ed Rubel's work and recent findings that birds can regenerate their hair cells—a capacity humans lack spontaneously. By studying these pathways in birds, researchers hope to apply this knowledge to humans. In particular, Stefan Heller's work at Stanford is examining how to reawake these pathways in mammals for precise regeneration needs. This understanding could be a breakthrough for therapy insights and hair cell regeneration therapies in humans.

The Potential of New Technologies Like Cochlear Implants

Cochlear implants are highlighted as a significant medical device capable of restoring hearing for individuals with severe loss. Stankovic touts cochlear implants as the most successful neural prosthesis, now commonplace and covered by insurance, that bypass nonfunctional hair cells in the inner ear and directly stimulate the auditory nerve. Huberman and Stankovic acknowledge the transformative impact of cochlear implants on individuals in the deaf community. Additionally, people with musical training tend to appreciate music more post-implantation, supporting the adaptability of the brain.

Personalized Management of Tinnitus and Auditory Disorders

Tinnitus, characterized as a phantom sound produced by the brain, typically exacerbates when focused on. Stankovic emphasizes that complete evaluations are conducted in clinical practice to rule out serious issues before assuring patients about the nature of tinnitus. Interventions like cognitive behavioral therapy a ...