Glossary

Acoustics (derived from the Greek akustikós meaning “hearing,” “heard”) – the science concerned with sound, i.e. flexural vibrations and waves in gases, fluids and solids, which are audible by the human ear (frequencies of such vibrations are within the range of 16 Hz–20 kHz).
Acoustic Feedback (AFB) – an occurrence manifesting through ghost signals (noises, hissing sounds, etc.) at an instrument’s output due to the penetration of signals from the acoustic output into the acoustic input.
Audiometer (obs. “авдиометр” in Russian; derived from the Latin audire meaning “to hear” and the Greek metron meaning “to measure”) – a device for the precise evaluation of hearing acuity – an electroacoustic device used to measure hearing acuity. By the nature of the signal that is used to measure hearing, audiometers are divided into pure-tone and speech categories; these are often combined in one single instrument.
When using a pure-tome audiometer, hearing acuity is determined by the audibility thresholds of pure (i.e. sine) tones; when using a speech audiometer – either by the audibility thresholds or speech intelligibility thresholds, i.e. by the minimum sound intensities, at which a satisfactory percentage of speech signal intelligibility is ensured.
The measured audibility thresholds are measured in decibels against statistically average normal hearing thresholds. The difference in decibels between the measured and normal thresholds quantifies the loss of hearing.
The audiometric method is used to determine hearing loss based on measuring the psychophysical parameter of the limen. This parameter is measured by changing the frequency and volume of the sound. Research data suggests that sounds the frequency and volume of which are closest to those of human speech are the most distinguishable.
Audiogram – a graph of the audiometric test findings recorded in a special form with horizontal and vertical axes. The vertical axis corresponds to the sound level (intensity) in dB HL (decibels in hearing level); frequencies in Hz (hertz) are along the horizontal axis. The red curve on the audiogram corresponds to the right ear; the blue one – to the left ear. Examination data obtained using headphones is shown as a solid line; data obtained with a bone vibrator – as a dash-line. There are no counter-indications for or complications of the examination; it is carried out when selecting the hearing aid and usually lasts about 20 to 40 minutes.
Binaural fitting – bilateral prosthetic hearing aids (on both ears).
Decibel (one tenth of a bel; dB) – measuring unit of the sound’s level. It is called after one of the inventors of the telephone, Alexander Graham Bell (1847–1922). The sound loudness scale in decibels has been developed.
Threshold of discomfort – the threshold value of the sound volume that causes a feeling of uneasiness in the user; it is measured in decibels. It is taken into consideration when tuning up the peak values of the output acoustic pressure of the hearing aid.
Custom Ear Mold (CEM) – 1) an ear mold made using an impression of the external ear and external acoustic meatus; 2) a part of the modern day prosthetic device which substantially defines the success of the choice and tuning up of the hearing aid. It is made using an ear impression in accordance with its dimensions.
BEI Functions – latching the hearing aid behind the patient's ear; transmitting the sound from the hearing aid to the drum membrane and ensuring optimum sound; prevention of the occurrence of any feedback (“hissing noise”) in the hearing aid; prevention of chafing and irritation of the skin of the external acoustic meatus.
Cochlear Implantation – a surgical procedure, during which an electrode system is inserted in the patient’s ear to ensure perception of acoustic data through an electric stimulation of the intact acoustic nerve fibers. CI is a way of fitting a patient with hearing aids.
Logopedics – the science concerned with the laws of development, upbringing, teaching, social adaptation and integration into society of children with speech pathologies, but with normal hearing.
Oligophrenopedagogics – the science concerned with the laws of development, upbringing, teaching, social adaptation and integration into society of children with mental retardation.
Verification of measuring equipment – a set of operations performed by agencies of the National Metrological Service (or other duly authorized bodies or institutions) with the view of determining and verification of compliance of the measuring equipment’s parameters with the specified requirements. The Interstate Council for Standardization, Metrology and Certification (of the CIS countries) has specified the following types of the verification:
Primary verification
Periodic verification
Exceptional verification
Official verification
Integrated verification
Component-wise verification
Verification by sampling
Expert verification
Advanced training (qualification improvement) – training personnel with the view of improving their knowledge, expertise and skills, as necessary due to heightened requirements for the profession or a career promotion. The goal of advanced training is to update the specialist’s theoretical and practical knowledge in compliance with the continuously rising requirements of the national educational standards. Advanced training shall be provided when necessary, but in any case at least once per 5 years throughout the personnel’s labor activities. The frequency of advanced training for the specialists shall be established by their employer. Advanced training includes the following types of trainings: short-term (at least 72 hours), theoretical and topical workshops (72 to 100 hours) devoted to research engineering, technological, socioeconomic and other issues encountered by an industry or entity; long-term (over 100 hours) trainings of specialists organized at educational competence development institutions for the in-depth study of the challenging scientific, engineering, technological, socioeconomic and other issues, depending on the professional profile.
Personnel retraining – training personnel with the view of mastering knew knowledge, expertise and skills due to changed requirements for the labor deliverables, or for acquiring a new profession.
Сhild (children) with disabilities – a child (children) under eighteen with physical and/or mental disorders and disabilities caused by inborn, genetic, evoked diseases or consequences of injuries certified in due order.
Speech Audiometry – a subjective method to diagnose a hearing impairment that allows to determine the percentage of words a person can distinguish at different volumes of sound.
Hearing aid – 1) a device of any kind designed to compensate a person’s hearing loss disabilities, for which the setup of operating parameters is ensured by an interface and a control device; 2) an electronic device designed to amplify the sound via air or bone conduction; 3) a sound-amplifying device to be used in case of a persistent hearing impairment or deafness.
Fitting with hearing aids – an electroacoustic hearing correction by means of correction devices or through a compensation of the lost hearing (hearing aids).
Center of audiology – a medical and preventive treatment facility that offers hearing correction by means of fitting patients with hearing aids with the view of social rehabilitation of both children and adults.
Educational audiology – the science concerned with the laws of development, upbringing, teaching, social adaptation and integration into society of children with impaired hearing (deaf since birth, acoustically challenged, who have lost hearing).
Special pedagogy – the science concerned with the essence, laws, trends in the management of the development process of the individuality and personality of a physically or mentally challenged child who needs special individualized methods of upbringing and teaching due to their physical or mental challenges.
Tiflopedagogics – the science concerned with the laws of development, upbringing, teaching, social adaptation and integration into society of children with profound visual impairments (with partial sight, visually impaired, who have lost their sight, are blind since birth).
Hearing loss – a partial loss of hearing. There are three types of hearing loss: one is predetermined by improper sound conduction (conductive hearing loss), hearing loss caused by improper sound perception (sensorineural hearing loss) and combined hearing loss. Conductive hearing loss is associated with a pathology of the sound conducting system of the external, middle or inner ear, which comprises: the external acoustic meatus, drum membrane, auditory ossicles, and fluids in the inner ear. Sensorineural hearing loss is caused by a pathology of the inner ear’s sound perception system. The key functional components of this system are the organ of Corti and special cochlear hair cells which are a part of the organ and responsible for transforming the mechanical vibrations of the fluid in the cochlea into a bioelectrical signal that is further transmitted to the acoustic nerve. Combined hearing loss is a combination of the above two pathologies.