Characteristics of Hearing in Elderly People

Abstract

The authors define the term presbycusis and discuss the prevalence of hearing loss in elderly people, its etiology, and methods of diagnostics (anamnesis, evaluation of the peripheral and central parts of the hearing system). The authors emphasize that central auditory processing disorder (CAPD) significantly impairs speech perception in elderly people and makes difficult the rehabilitation of patients with presbycusis. The possibility of improving speech intelligibility by using auditory training is considered. Improved functioning of the central auditory pathways in hearing aid (HA) users with moderate to moderately severe chronic sensorineural hearing loss (SNHL) and symptoms of CAPD was shown after the auditory training with the use of two approaches ("bottom-up" and "top-down"). The algorithm of the auditory training was designed based on distinction between nonverbal and verbal stimuli of varying complexity, as well as tasks to improve memory (e.g., memorizing poetry). The benefits of the auditory training in the rehabilitation of HA users with low speech intelligibility were demonstrated. Improvement of speech intelligibility in elderly patients with SNHL proves that plasticity of the auditory regions of the brain remains possible throughout the life. Options of the presbycusis prophylaxis are summarized.Different authors sometimes interpret this term differently. Some researchers meant (imply under this term) age-related hearing disorders caused by involutional changes only in the cochlea, and others meant that changes involve all parts of the auditory system [1,2]. Presbycusis is considered to be one of the forms of progressive SNHL, which is associated with age-related involutional changes of different parts of the hearing system and is presented by symmetric pure tone audiogram with flat loss toward high-frequency range (less steep than 20 dB/oct) [3]. Numerous studies are dedicated to anatomical and functional risk factors of the presbycusis [4][5][6][7][8][9]. The significance of the presbycusis problem is determined by its social importance, lack of data about its etiology, and need for clinical practice to accurately determine an impaired area of auditory system and to identify the presbycusis genesis. PrevalencePresbycusis is a rather common disorder. According to the World Health Organization (WHO), more than 5% of global population (about 328 millions of adults) suffers from any degree of hearing loss, while among people older than 65 years of age, the prevalence of hearing loss exceeds 30% [10].Its prevalence increases every year that may be due to the general trend of increased life duration-much more adults reach aged (from 60 to 74 years old according to the WHO classification) and senile (75 years old and more) periods. The world population is rapidly aging. At the period between 2000 and 2050, the proportion of the world's population over 60 years will double from about 11 to 22%. The absolute number of people aged 60 years and over is expected to increase from 605 million to 2 billion ov...

Age-Related Hearing Loss, Traditional Compilation

“…Peripheral auditory sensation is then evaluated by audiologic tests. Evaluation of the peripheral auditory system includes basic audiological evaluation methods that can be listed under two titles as subjective tests (pure-tone audiometry, speech audiometry) and objective tests (immittance and otoacoustic emission tests) (2,12). Pure-tone audiometry and speech audiometry tests provide very useful information for the determination of the appropriate intervention and the comparison of pre-and post-intervention results.…”

“…Hearing is a complex function involving various mechanisms. These mechanisms and functions are affected by aging (1,2). As a replacement of the term "presbycusis" which was first used by Zwaardermarker in 1893 and means "hearing loss in the older age" (2) the term "age-related hearing loss" (ARHL) is preferred today (3).…”

“…This rate increases every year depending on the prolongation of life duration. The ratio of the elderly population to the total population in the world will reach about 22% (1.2 million) by 2050, and more than 500 million elderly individuals will substantially be affected by age-related hearing loss (2,4). On the other hand, our country is estimated to have 20.8% elderly in 2050 (5).…”

“…Age-related hearing loss is interpreted differently by researchers. While some researchers define it as a hearing disorder resulting from changes in the cochlea caused by aging, others describe it as a hearing disorder arising from the changes in all the sections of the auditory system (2).…”

“…However, contrary to this classification, there are many causes of agerelated hearing loss. Age-related hearing loss does not result only from changes in the inner ear but also changes in the middle ear or multiple changes along the nerve pathways (2). Studies on conductive hearing loss in elderly people have attracted less attention than other categories for years.…”