Types of listening devices
- A simple microphone which connects to you by means of a wire. The sound comes either through a telecoil loop which is worn around the neck (telecoil setting is needed on the hearing aid) or via a stethoset. For those who do not wear a hearing aid the stethoset is useful. This is worn like a light plastic stethoscope. This is the least expensive method, but wires can be a nuisance and some people prefer a radio (wireless) link.
Photos – stethoset and hearing loop
- A microphone which picks up the sound which connects to a receiver worn by you wirelessly. The microphone therefore can be worn conveniently on the speaker who can be some distance away. The reciever connects to the ear either by stethoset (non-hearing aid users) or telecoil loop around the neck (telecoil setting is then needed on the hearing aid).
- A microphone as in (2) above which connects wirelessly direct to the hearing aid without the need of a separate receiver. This system is, at present, available for most BTE (behind the ear) hearing aids. Recently however certain other hearing aids can accommodate the technology. One would need to enquire of the audiologist as to the availability. The receiver on the BTE hearing aid is in the form of a small shoe which fits onto the bottom of the hearing aid. This is known as an ear level receiver. This shoe has to be purchased at the same time and needs setting up by an audiologist. This method is more expensive but is certainly extremely convenient. The ear level receiver also eliminates the electronic hum so often a nuisance with neck loops (for instance neck loop use in a car). Neck loops are unsightly and get in the way of clothing. The only disadvantage is that the battery of ear level receivers do not last as long and obviously the cost involved.
Photo – hearing aid shoe
- There are other methods of transfer of sound from the source to you. Bluetooth is one of these. Some listeners are Bluetooth compatible. This is certainly something which should be explored at the point of purchase. Bluetooth is helpful for listening to television, the telephone to MP3 players and other uses.
- Other methods use an infra-red signal. These require a direct line of sight between the transmitter and the receiver (for which a telecoil neck loop is needed). They are therefore limited in use for a single purpose for instance listening to the TV or in a theatre or cinema.
Hearing aids are designed individually to compensate for the particular loss in each person. The sound is boosted where the audiogram suggests the need. With the more severe degrees of hearing loss boosting the sound at those frequencies where the hair cells are not working may not help. The sound volume will be improved but not necessarily the clarity of the speech. This is further explained in Audiology.
This should be born in mind when considering the purchase of an expensive listening device. All devices should be tried out before accepting the purchase. If they don’t work for you then they should be returned. A full refund should be requested and made provided of course that it has not been damaged.
In general speech the vowels are easier to hear. A E I O and U. These are low frequency pitch. It is the consonants which pose the problems, especially the higher frequency consonants, Ps and Bs and Vs and th sounds. Audiology