The macular organs (sacculus and utriculus) are parts of the vestibular labyrinth and register linear acceleration and gravitational influences. They contain hair-filled sensory cells whose stereocilia are embedded in a gelatinous membrane weighted with otoliths (calcium carbonate crystals). Shifts in the otoliths when the head is tilted or accelerated bend the stereocilia, triggering nerve impulses. This information is transmitted to the brain via the vestibular portion of the VIII cranial nerve and combined with visual and proprioceptive data to determine position. Damage to the macula organs leads to unsteadiness when standing and walking, as well as pathological swaying.

A malformation syndrome of the ear includes congenital malformations of the outer ear, middle ear, or inner ear, often in the context of genetic syndromes such as Goldenhar syndrome or Treacher Collins syndrome. Those affected show auricular malformations (microtia, anotia), ear canal atresia, or cochlear malformations. Hearing loss ranges from mild conductive hearing loss to complete deafness, depending on the extent of the malformation. Treatment includes surgical reconstruction, bone conduction hearing aids, or cochlear implants. Multidisciplinary care by ENT surgeons, audiologists, and plastic surgeons is crucial for functional and aesthetic results.

The mandibular reflex, also known as the chin reflex, is triggered by tapping on the lower jaw and tests trigeminal motor function. Although primarily a neurological test, the chewing muscles influence the auditory canal due to their proximity and can contribute to ear pain and tinnitus in cases of temporomandibular joint disorders. An increase or decrease in the reflex may indicate central or peripheral nerve lesions. In ENT diagnostics, it is combined with other cranial nerve reflexes to differentiate between headache and ear symptoms. Treatment for malfunction is provided through craniomandibular therapy and physical therapy.

Masking is the superimposition of a test signal with a noise or tone mask to prevent the untested ear from responding during audiometry (cross-hearing). It is necessary when the level difference between air and bone conduction allows unwanted perception in the opposite ear. Masking levels are calculated according to standardized rules to ensure the validity of threshold determination. In psychoacoustics, masking also refers to the suppression of quieter sounds by loud neighboring frequencies. In hearing aids, targeted masking is used to cover up tinnitus or reduce background noise.

The mastoid (mastoid process) is the bony protrusion behind the auricle, which contains air-filled cells and is part of the temporal bone. It serves as a buffer for middle ear infections, but can itself become inflamed in cases of chronic otitis media (mastoiditis). Clinically, the mastoid is palpated for pressure pain and swelling to detect complications. Imaging techniques (CT) show cell structure and the extent of inflammatory processes. Surgical mastoidectomy removes diseased tissue and preserves hearing function.

The external auditory canal is the outer ear canal that conducts sound from the auricle to the eardrum. It consists of bony and cartilaginous parts and is lined with skin and cerumen glands. Cerumen formation and exostoses can narrow the canal and lead to sound conduction disorders. Otoscopic examination checks the width, skin condition, and foreign bodies. In hearing aid fitting, a precise fit of the earmold in the meatus is crucial for attenuation and freedom from feedback.

The medial olive complexes in the brainstem are central switching stations for binaural auditory processing. They compare interaural time differences (ITD) to determine the direction of low-frequency sound sources. Neurons in these nuclei fire in phase with the sound waves and transmit information to higher auditory centers. Lesions lead to directional hearing disorders and reduced speech comprehension in noise. Research uses electrode recordings to analyze the precise temporal coding in the olive nuclei.

In audiology, the membrane usually refers to the eardrum, a three-layered structure that converts sound energy into mechanical vibrations. It separates the outer ear from the middle ear and transmits vibrations to the inner ear via the ossicular chain. Changes in thickness, tension, or integrity—such as perforations—affect impedance and hearing ability. The membrane also plays a role in otoacoustic emissions, as its reflections can be measured. Surgical repairs (tympanoplasty) reconstruct damaged membranes to restore sound conduction.

The tectorial membrane is a gelatinous covering in the organ of Corti that lies over the hair cells and brushes their stereocilia when sound is induced. It transmits traveling waves from the basilar membrane into lateral movements of the hair cell stereocilia, which triggers mechano-electrical transduction. Differences in the stiffness and mass of the tectorial membrane along the cochlea influence frequency selectivity. Damage or detachment of this membrane leads to hearing loss and impairs tonotopy. Research approaches are investigating biomaterials for the regeneration of the tectorial membrane after noise damage.

Ménière's disease is an inner ear disorder characterized by episodes of vertigo, fluctuations in hearing, tinnitus, and ear pressure. Pathophysiologically, it involves endolymphatic hydrops, i.e., an overflow of endolymph into the cochlear duct and semicircular canals. The diagnosis is based on clinical criteria, audiograms, and the exclusion of other causes. Treatment includes diuretics, intratympanic gentamicin administration for vestibular ablation, and vestibular training. Despite its chronic course, symptom control can significantly improve quality of life.

The mesotympanum is the middle section of the tympanic cavity in the middle ear between the epitympanum and the hypotympanum. It contains the ossicular chain and the stapes attachment at the oval window. Pathologies such as effusion or cholesteatoma often manifest in the mesotympanum and impair sound conduction. Surgical procedures (tympanotomy) aim to clean and ventilate this area. Tympanometry can indirectly estimate the pressure and volume in the mesotympanum.

Misophonia is a neurological-psychiatric disorder in which certain everyday sounds (e.g., chewing, typing) trigger intense negative emotions such as anger or disgust. Those affected react with an increased stress response, which severely limits social interaction and quality of life. The exact mechanisms are still unclear; a misconnection between auditory areas and the limbic system is suspected. Treatment approaches include cognitive behavioral therapy, tinnitus desensitization, and mindfulness exercises. Audiological examinations rule out organic hearing disorders to confirm the diagnosis.

The middle ear is an air-filled cavity that contains the eardrum, ossicular chain (malleus, incus, stapes), and Eustachian tube. It adapts sound pressure from air conduction to fluid conduction in the cochlea and protects against loud noises through reflexes. Diseases such as otitis media, otosclerosis, or cholesteatoma impair sound conduction and lead to hearing loss. Diagnosis is made by otoscopy, tympanometry, and audiometry. Surgical procedures such as stapedotomy or ear tubes improve ventilation and conductivity.

Otitis media is an inflammatory disease of the tympanic cavity, often caused by viruses or bacteria. It causes earache, fever, hearing loss, and can lead to fluid build-up. Chronic otitis media can lead to complications such as perforation of the eardrum or cholesteatoma. Treatment includes antibiotics, pain therapy, and, in the case of effusion, ear tubes. Prevention through vaccination (pneumococcus) and treatment of throat infections reduces the incidence.

The modiolus is the central bony axis of the cochlea around which the cochlea coils. It contains nerve fibers of the auditory nerve that run from the hair cells to the brainstem. The close spatial arrangement in the modiolus facilitates electrical stimulation during cochlear implantation. Pathologies such as fibrosis of the modiolus can impair implant function. In imaging, the modiolus is measured to plan surgical approaches.

Monaural hearing refers to hearing with only one ear, which eliminates binaural advantages such as localization and noise suppression. Those affected often compensate by moving their head and using visual cues. Audiologically, a monaural audiogram is evident, and masking is not necessary. Monaural fitting with only one hearing aid can maintain speech comprehension in quiet environments, but is severely limited in noisy environments. Support strategies include FM systems and room acoustics optimization.

Mondini dysplasia is a congenital malformation of the cochlea with reduced turns (usually 1–1.5 instead of 2.5). It belongs to the spectrum of inner ear malformations and leads to sensorineural hearing loss to varying degrees. Vestibular structures are also frequently affected, which can cause dizziness. Diagnosis includes high-resolution CT and hearing tests, and treatment often involves cochlear implantation. Early intervention improves speech development and balance function.

Ménière's disease is a chronic, recurrent disorder of the inner ear in which endolymphatic hydrops is accompanied by periodic attacks of vertigo, ear pressure, tinnitus, and fluctuating hearing loss. The term "Ménière's syndrome" is also used when the symptoms are incomplete or secondary to other diseases. The diagnosis is based on clinical criteria and the exclusion of other causes of vertigo using audiometry and balance tests. Treatment approaches include a low-salt diet, diuretics, intratympanic gentamicin injections, and vestibular rehabilitation training. Despite treatment, irreversible hearing loss in the affected frequency ranges may occur in the long term.

The stapedius muscle is the smallest striated skeletal muscle in the body and originates at the pyramidal process of the temporal bone. It is connected to the stapes by a tendon and reflexively pulls it back when stimulated by high-level contrast. This contraction—the stapedius reflex—reduces sound transmission to the inner ear and protects it from harmful loud noises. Its function is tested in tympanometry by measuring the change in middle ear impedance during acoustic stimulation. Impairment of the stapedius muscle, for example due to nerve lesions, leads to increased noise sensitivity and hearing disorders.

The stapedius reflex is an acoustically triggered muscle reflex in which the stapedius muscle contracts at levels above approximately 70–90 dB SPL. This stiffening of the ossicular chain dampens loud impulses and protects the sensitive hair cells in the inner ear. The reflex is measured diagnostically using tympanometry devices that record changes in impedance and reflex latency. A missing or asymmetrical reflex may indicate otosclerosis, facial nerve lesion, or central auditory pathway disorder. Reflex parameters provide important information for the differential diagnosis of middle ear and neural pathologies.

Myoelectric stimulation uses electrical impulses to activate specific muscles and provide therapeutic training or relaxation. In ENT practice, it can be used to treat tinnitus, chronic muscle tension in the jaw and facial area, and to improve Eustachian tube function. Electrodes apply weak direct or alternating currents through the skin, triggering muscle contractions. Patients report pain relief and improved functionality after regular sessions. Scientific studies are currently investigating optimal stimulation parameters and long-term effects.

Myringitis is an inflammation of the eardrum that can be caused by viral or bacterial infection, excessive heat, or chemical irritants. Those affected complain of acute ear pain, redness, and swelling of the eardrum, and occasionally fluid discharge. Clinically, myringitis can be recognized otoscopically by a cloudy or hyperemic membrane. Treatment includes analgesics, topical antibiotics if necessary, and avoidance of further irritants. Complications such as perforation or chronic inflammation are rare but possible.

Myringoplasty is a surgical procedure to reconstruct the eardrum in cases of perforation, usually with the aid of a connective tissue graft (e.g., fascia or perichondrium). The aim is to restore sound conduction and prevent recurrent otorrhea. Access is often retroauricular or endaural, followed by microsurgical suturing and covering of the defect. Success rates for permanent eardrum closure are over 85%. Postoperative audiometry checks hearing gain, and hygiene measures reduce the risk of infection.

Myringoscopy is the visual inspection of the eardrum and tympanic cavity using an otoscope or surgical microscope. It allows the color, permeability, perforations, and other pathologies of the membrane to be assessed. If necessary, samples can be taken via an instrument channel for microbiological or histological examination. Myringoscopy is routine in ENT clinics and forms the basis of all middle ear diagnostics. Clinically, the findings guide further treatment decisions, such as tympanostomy tube insertion or myringoplasty.

Myringotomy is a small incision in the eardrum to drain acute effusion or pus from the middle ear. It is often performed in combination with the insertion of a tympanostomy tube to ensure permanent ventilation. It is indicated for acute middle ear surgery, chronic effusions, and pressure pain. The procedure is performed on an outpatient basis under local anesthesia and takes only a few minutes. Rapid relief usually leads to immediate pressure reduction and improved hearing.