A.1 Introduction Electrocochleography (ECochG) is the recording of stimulus-related potentials generated in the human cochlea and the auditory nerve. These potentials are the cochlear microphonics (CM), the summating potentials (SPs), and the compound action potential (CAP). There are three important applications of ECochG: (1) correlation of physiological and psychoacoustic properties, (2) investigation of certain diseases, and (3) objective diagnosis of individual cases of deafness ( ).…

First we briefly review the potential of gene therapy for hereditary hearing loss and for generating new hair cells in deaf ears. 13.1 Gene Therapy for Hereditary Hearing Loss About 15% of hereditary deafness is inherited as autosomal dominant nonsyndromic hearing loss (see chapter: Epidemiology and Genetics of Hearing Loss and Tinnitus ). Examples include GJB3 (DFNA2), GJB2 (DFNA3), GJB6 (DFNA3), and possibly also DFNA4, DFNA9,…

Persons who lack an auditory nerve (AN) cannot benefit from cochlear implants (CIs), but a prosthesis utilizing an electrode array implanted on the surface or in the cochlear nucleus (CN) can restore some hearing. Worldwide, more than 1200 persons ( ) have received these auditory brainstem implants (ABIs), most commonly after removal of the tumors that occur with bilateral vestibular schwannomas (Type 2 neurofibromatosis, NF2). Most…

Cochlear implants are among the great success stories of modern medicine. Thirty years ago these devices provided little more than a sensation of sound and sound cadences—they were useful as an aid to lip-reading. In the 1980s, however, systems with multiple channels of processing and multiple sites of stimulation in the cochlea were developed and these systems supported significantly higher levels of speech reception than their…

Implantable hearing aids (IHAs) can roughly be divided in bone-anchored hearing aids (BAHAs) and middle ear implants, both are mostly indicated for conductive hearing loss. However, middle ear implants are also a good solution for patients with sensorineural hearing loss who cannot tolerate ear molds because of external otitis. At the end of the 20th century, noted that “this is an extremely dynamic field and there…

What do people expect from hearing aids (HAs)? HAs are not—as many new users expect—the auditory equivalent of contact lenses or glasses that instantly restore all aspects of hearing. That would only apply for their use to compensate for a pure conductive hearing loss. HAs in their basic form consist of a microphone, an amplifier with frequency specific gain and amplitude compression, and a miniature speaker.…

Humans hear long before they are born. The human cochlea is fully developed by 24 weeks of gestation. A blink-startle response can already be elicited (acoustically) at 24–25 weeks and is constantly present at 28 weeks. Hearing thresholds are 40 dB HL at 27–28 weeks and reach the adult threshold by 42 weeks of gestation, i.e., at term birth ( ). Still, the central auditory system…

Hearing loss occurs in children and in the elderly, in war veterans and factory workers, and in classical musicians and disc jockeys. Epidemiology is the study of factors such as hearing loss that affect the health and illness of populations and serves as the foundation for interventions made in public health and preventive medicine. Two quantifiers are frequently used; prevalence is defined as the percentage of…

Noise-induced hearing loss (NIHL) is most likely the dominant cause of acquired hearing loss. In turn, the fastest growing causes for NIHL is the use of personal listening devices (PLDs) and exposure to occupational noise including music performances. Extensive information has recently been published in the work of , and I use information from that book in this chapter to make it self-contained. Ototoxiciy, long-lasting effects…

Peripheral hearing loss comes in two broad types, conductive and sensorineural. Conductive hearing loss results from deficits in the sound-conducting apparatus of the outer and middle ear. Problems such as fluid in the middle ear and immobility of the middle ear bones are the main cause of a conductive hearing loss. Sensorineural hearing losses (SNHLs) that result from damage to the hair cells and the stria…

Imagine that your hearing sensitivity for pure tones is exquisite—not affected by frequent exposure to loud music or other noises—but that you have great problems in understanding speech even in a quiet environment. This occurs if you have a temporal processing disorder. Although hearing loss (HL) is in the ear, hearing problems originate in the brain. We often take hearing for granted; not realizing what good…

3.1 Multimodal Auditory Cortical Areas Examples in Chapter 2 , Brain Plasticity and Perceptual Learning show that perceptual learning is more efficient when the training is multisensorial. Here we will review that combining the information from different senses is essential for successful interaction with real-life situations. It is often believed that this integration occurs at later processing stages and mostly in higher association cortices ( ),…

The brain—young as well as adult—has the capacity to adapt in response to changes in the external environment, to changes in the sensory input due to peripheral injury such as hearing loss, and as a result of training (perceptual learning). Brain plasticity is a determining aspect of the potential success of hearing aids and cochlear implants (CIs). It basically allows the user to adjust to the…