Transcript Lipreading Teachers’ Training Course

Hearing aids – different types
Objectives
Understand why different aids suit different types of hearing loss
Understand how the different types of hearing aids work
Relevant for: Assignment 1 c Hearing aids
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Different types of hearing aid
Behind-the-ear (BTE)
Bone conduction
In-the-ear (ITE)
Bone anchored (BAHA)
In-the-canal (ITC) and
completely in the canal
(CIC)
CROS/ BiCROS
Open-fit
Body worn
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Receiver-in-the-ear (RITE)
Receiver-in-the-canal (RIC)
Wireless FM
Behind-the-ear (BTE) aids
• Suitable for most hearing losses.
• The type of aid generally provided by the NHS.
• Most have a telecoil (‘T’ setting to use with a loop
system and/or radio aid) and direct audio input
connection (to use with a radio aid)
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Analogue and Digital – the key difference
Analogue
The electric signal from the microphone is amplified “as is” and it is
then transformed back to acoustic sounds using the speaker.
Digital
The electric signal from the microphone is transformed to bits and
bytes of digital information and manipulated by the most advanced
digital technology.
The signal is transformed back acoustic sounds.
Key difference
A digital aid can be programmed to adapt more precisely to the
specific hearing loss but may not give such a ‘true’ sound.
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Pros and cons of digital aids
Pros
Different programmes for different listening environments
Adjust automatically
May reduce feedback
Programmed to suit individual’s hearing loss
Can aid more difficult losses
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Real ear measurement (REM) with digital aids
Part of the new hearing aid fitting procedure
Shape/size of ear canal varies from person to person
Measures the effects of the ear canal on sound
Audiologist can adjust the hearing aid accordingly
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Pros and cons of digital aids
Cons
Volume changes automatically – lack of control
Batteries fall out when aid off
Fitting times longer
Staff need more training
More costly
Expectations may be too high
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In-the-ear aid (ITE)
In-the-canal aid (ITC)
Completely in the canal aid (CIC)
Not suitable for severe hearing losses.
No telecoil or direct audio input connection
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Open fit (behind-the-ear-aids)
with tips/domes
Suitable for mild to moderate hearing loss
No earmould needed
Can be issued on the day of the hearing test
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Receiver-in-the-ear (in the canal) aid RITE (RIC)
Speaker is in ear canal
• Less feedback
• No distortion through tubing
• Part of aid behind the ear is smaller
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Body-worn hearing aids
For very severe hearing loss
Manual dexterity problems
Learning disability
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CROS aid
(Contralateral routing of signals)
Wired
Sound routed from ‘deaf side’
to good side
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Wireless
Sound transmitted wirelessly
to good side
Wireless FM
Can alter programme with remote
Communication with both hearing aids
Blue tooth enabled hearing aids
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Traditional bone conduction hearing aids
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Bone anchored hearing aid (BAHA)
Clips onto a screw implanted into the skull
behind the ear.
Sound is transmitted by vibration into the
cochlea (inner ear).
Most have a direct audio input connection
and an optional plug-in telecoil
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Hearing aids - developments
Improved directional microphone systems
• Automatic feedback cancellation
• Better background noise reduction
• Water resistance (Phonak, Siemens)
• Increased higher frequency range
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