|
Category of Hearing Loss
|
Category and Range of Hearing Loss |
Communication Ability
|
Mild Hearing Loss |
Hard to identify soft sound but capable ofgeneral communication.
|
Moderate Hearing Loss |
Hard to receive voice over 2 meters. The use of hearing
aids can improve receptive power.
|
Moderately Severe Hearing Loss |
Hard to hear soft voice in general communication. Should
use hearing aids to improve reception.
|
Severe Hearing Loss |
Hard to communicate fluently with people. Speech is deflected.The
use of hearing aids is crucial in communication. Lip reading improves
reception.
|
Profound Hearing Loss |
Speech is deflected and possibly language is deviant.
Communication with people relies heavily on the use of hearing aids and
lip reading.
|
A.3.1 Individual Hearing Aids :
Wireless Individual Hearing Aid
The Wireless Individual Aid allows the hearing impaired children with greater mobility to join in the classroom activities.
Cochlear Implant
An artificial cochlear is implanted into the ear by surgery. After the operation, the implantee still needs to wear the speech processor and transmitter to transfer voices into electric impulse.
Behind the Ear hearing Aid
This is the most common type of hearing aid used by the hearing impaired children. This hearing aid amplifies sound for greater audibility.
Radio FM Group Hearing Aid
There is a transmitter for the teacher and ten receivers for the hearing impaired children. During the lessons, the children receive the FM signal from the teacher without the obstacle of the wire. A greater mobility for activities in the classroom is allowed.
A.3.2 Group Hearing Aids in a Deaf School :
Group Hearing Aids
The children's desks are arranged in a horse-shoe shape unit. There are ten sets of Pupil Unit on the desk.
Headphone and Pupil Unit
Each set of Hearing Aid has a headphone and a pupil unit. Hearing impaired children can adjust the volume, tone and AGC according to their needs.
Teacher Unit
The Teacher Unit in each classroom helps to control all the Pupil Units. Teacher can control the sensitivity level of the microphone in order to have the best output level to the Pupil Units.
Radio FM Group Hearing Aid
The radio FM group hearing aid is used in the Primary classes. The FM wave transmits the signal from the teacher to the children without the obstacle of the wire. The children are provided with greater mobility to participate in the classroom activities.
A.3.3 Hearing Aids used in Speech Training Room :
Speech Trainer
There are speech rooms in the deaf schools. The speech trainer in the speech room can be adjusted to meet the auditory needs of the child. The teacher can communicate with the child using the microphone. The child can also input his own speech with the help of the microphone.
Speech Viewer
This is a specially designed computer that provides attractive visual image to motivate the child to speak.
It helps to check the child's articulation of the /s/ sound.
Audiogram
An audiogram is a chart which locates the hearing threshold at different frequency. The horizontal axis reads in frequency (pitch) and the vertical axis reads in decibels (loudness). The frequencies are low on the left hand side (e.g. 125Hz) and the highest frequency (8000Hz) is on the right hand side. The loudness scale goes from very soft sounds (e.g. -10dB) at the top of the vertical axis, to very loud sounds at the bottom (e.g. 130dB).
An audiogram is prescribed by an audiologist. In Hong Kong, each audiogram of the school aged children is renewed every two years. An audiogram, which shows the residual hearing of the child, helps educators to plan the teaching objectives.
Legend of an audiogram :
The 'X' represents the hearing threshold of left ear. The 'O' represents the hearing threshold of right ear. The 'D' represents the hearing threshold of bone conduction.