Hearing aids – aids and amplification
In order to develop language, the child must be allowed access to sounds of speech. In cases where the child has a hearing impairment, it is very important to provide amplification at the earliest age and as close as possible to detection of the impairment.
The installation of hearing aids or the cochlear implant provides accessibility to speech and environmental sounds, thus enabling the maturation of the auditory system (the hearing system). The auditory learning process encourages maturation and improves the ability to decipher sounds and speech. Consistent wearing of the hearing aids throughout the child’s waking hours allows the auditory learning process to begin. The child’s auditory experience should be adapted to his or her age, his or her level of development and interests. The development of the sequence of the child’s hearing skills should be intertwined with the disciplinary interaction with him or her throughout the day.
There are several types of amplification aids:
Hearing aids are an amplification device suitable in situations of mild to severe hearing loss.
The hearing aids have a microphone (one or two), which picks up the surrounding sounds. The microphone converts the acoustic stimulus into a digital signal. The converted signal is amplified by an amplifier and processed digitally. The amplified signal is converted (by a transducer) back into an acoustic sound (stronger than the one picked up by the microphone) and transmitted to the earphone located in the outer ear cavity. From here the sound is transmitted in the ear to the auditory nerve similar to the normal hearing process.
Today, it is common to fit children with digital hearing aids, which change their amplification level according to the changing acoustic environment, taking into account unique characteristics such as the size of the ears in babies and young children. The goal is to provide auditory accessibility to soft ambient and speech sounds, comfort for listening to speech and ambient sounds at an average intensity and to prevent discomfort from loud sounds.
Advanced digital hearing aids have a variety of mechanisms that enable precise adjustment and optimal amplification. The main ones include:
- Use of unique amplification formulas for young children.
- Noise filtering mechanisms.
- Speech detection and accentuation mechanisms.
- Division into a large number of channels.
- Directional microphones to improve speech understanding in the presence of background noise.
- Feedback canceling mechanisms (expressed in a beep).
- Using several listening programs for different environmental situations (such as speaking in a quiet environment, speaking in a noisy environment, music, etc.).
Some of these mechanisms are not recommended for use in the population of infants and young children.
Each company has hearing aids with different degrees of sophistication, which allows for the choice of the type of device and its direction according to the severity and nature of the hearing impairment of each of the ears.
At the Beit Micha Tel Aviv Audiological Institute, optimal hearing aids are fitted to the child according to the level of hearing loss data, according to his personal needs and according to his family’s preferences.
The cochlear implant is a hearing device that includes a surgically implanted part in the inner ear and an external system. The cochlear implant is suitable in situations of severe to profound hearing loss, when sufficient benefit is not obtained from the hearing aids.
The internal parts that are implanted in a surgical process include a magnet, a receiver and an electrode arc.
The external parts include a sound processor that includes a microphone and a transmission ring attached by a magnet.
The microphone in the sound processor of the cochlear implant system picks up the surrounding sounds. The acoustic signal is encoded into an electrical signal that represents the characteristics of speech and sounds. The coded signal is transmitted with the transmitter ring through the skin to the receiver in the implanted part. From there, this signal is transmitted to the array of electrodes located in the inner ear and stimulates the nerve fibers. From this stage the hearing process occurs similar to natural hearing, the nerve fibers transmit the information to the hearing centers in the brain for decoding.
Cochlear implant surgeries are performed in several transplant centers in Israel. The family chooses the transplant center and we at Beit Micha Tel Aviv accompany the child and the family throughout the entire process, from the stage of preparation for surgery, to the surgery and the rehabilitation process that follows and are in constant contact with the transplant center.
The FM system is an aid designed to improve speech understanding in conditions of background noise, distance from the speaker and reverberation. This system can be connected to the hearing aids or the sound processor of the cochlear implant, or as a separate personal or environmental system (such as speakers).
The FM system includes a microphone and a transmitter located with the speaker (such as the kindergarten teacher, teacher, parent, etc.), and a receiver connected to the hearing aids or the implant or to an environmental speaker. The system transmits radio waves wirelessly.
Using the FM system is recommended for children with hearing impairment in kindergarten and school and in difficult listening conditions. The system is also recommended for a wider range of users such as people with unilateral hearing impairment, hearing processing difficulties, attention and concentration difficulties and more.