The Jakobson effect describes the improved perception of speech sounds by briefly focusing on their acoustic characteristics, similar to phonemic "listening in". It occurs when listeners actively pay attention to certain frequency ranges and thus recognize nuances in consonants and vowels more clearly. This effect is used in speech therapy to treat articulation weaknesses. Audiological training programs reinforce the effect through targeted practice of individual phonemes. Neurophysiological measurements show increased cortical activity in auditory areas during the Jakobson effect.

The Jarisch-Herxheimer reaction is an acute inflammatory reaction following the death of bacteria, which can also rarely occur in the inner ear when ototoxic antibiotics kill bacteria in the cochlea. Toxins are released in the process, which worsen dizziness, tinnitus and hearing loss in the short term. The reaction usually sets in a few hours after the start of therapy and subsides within 24-48 hours. Steroids and antioxidants are administered symptomatically to reduce inflammation and oxidative damage. Knowledge of this effect is important to avoid confusing iatrogenic damage with treatment failure.

The Jensen test is a speech intelligibility test in which sentences or words are presented in different signal-to-noise ratios. It measures the minimum ratios at which speech can still be understood and quantifies hearing performance in realistic noise situations. The results help to adapt hearing aid programs to everyday conditions. Test variants use stationary noise or multi-speaker scenarios. The Jensen test is established in pediatric acoustics and adult rehabilitation.

The jet noise effect describes the broad frequency spectrum and high sound pressure levels generated by jet engines. Low and medium frequencies in particular travel over long distances and can lead to sleep disturbance and hearing stress in the vicinity of large airports. Noise measurements determine emission levels in order to optimize noise barriers and approach routes. Low-noise engine technologies and operating time regulations are used as preventative measures. Long-term studies document the effects on hearing and the quality of life of residents.

Itching in the ear canal is a common symptom of dry skin, eczema or allergic reactions to earmolds. It can lead to scratching and secondary infection if patients reach in with cotton buds or fingers. Treatment includes moisturizing ear drops, ointments containing corticosteroids and adjustment of earmold materials. A dermatological examination is recommended for chronic itching. Audiologists advise on skin care and hygienic cleaning of hearing aids.

The adolescent ear is the ear of a child or adolescent that is still developing anatomically and functionally. The ear canal, eardrum thickness and bone structure differ from adults and influence acoustic measurements. Audiological tests and hearing aid fittings must be calibrated to suit the child's age. Pediatric audiology programs take into account speech development and compliance. Long-term monitoring ensures that hearing loss diagnoses are detected and treated early.

The jugular sinus pressure in the mastoid region can indirectly indicate the intracranial and labyrinthine pressure via Valsalva maneuvers or pressure probes. It influences venous drainage of the inner ear and can lead to tinnitus or dizziness if the pressure is elevated. Clinically, it is tested in cases of suspected venous malformations or hydrocephalus. Imaging and Doppler ultrasound complement the pressure measurement. Therapeutic measures such as diuretics or surgical shunts may be indicated to relieve the pressure.

The Just-Noticeable Difference is the smallest perceptible change in an acoustic stimulus, such as frequency or volume, that a listener can just detect. It is determined psychoacoustically by presenting stimuli with minimal differences. JND values vary with frequency, base level and individual hearing condition. They are important for filter design and compression parameters in hearing aids. Small JNDs enable fine sound gradations, while large JNDs can limit speech comprehension.