| Hearing aids in the strictest form of the term have | | | | and the speakers were headphones. There was a little |
| been around for ever. When early man shouted a | | | | volume control, but on the whole, you got what it gave |
| greeting or a threat from a distance, the listener in all | | | | you. |
| probability cupped his hands behind his ears in order to | | | | These days hearing aids still work on the same |
| better hear what was being said to him. In general, | | | | principal, but micro technology has allowed |
| people did not live a long time up to several hundred | | | | manufacturers to miniaturize the device so that all the |
| years ago, especially the poor and the very rich, so | | | | components fit in one small unit, which is then put in or |
| being hard of hearing was not the problem that it is | | | | behind the ear. Most of these hearing aids can be |
| today. | | | | modified in some way to suit the wearer's personal |
| People were either born deaf or went deaf through | | | | hearing impairment. This is because not everyone is |
| illness. People did not go deaf through being old or | | | | impaired to the same degree and not everybody has |
| through industrial noise because their were no | | | | problems with the same frequencies. |
| machines. The poor died of hard work and illness and | | | | In addition, the environment you are in can make a lot |
| the rich were assassinated. Scholars and monks were | | | | of difference to the efficacy of the deaf aid and so, |
| possibly the only classes that lived into old age and | | | | modern units allow the wearer to filter out some |
| scholars were often monks and visa-versa. These | | | | ambient noises like wind rush or heavy machinery. |
| people were definitely clever enough to have invented | | | | There is also much more volume control than before. |
| the hearing trumpet from the cupped hand. | | | | Volume control can even be set to automatic. |
| But that is all that humans had for thousands and | | | | The basic form of hearing aid is the analogue device, |
| thousands of years. More of the sound (or vibrating | | | | the same kind as was first invented for batteries but |
| air) was caught by the cupped hand or trumpet | | | | much, much smaller. These are usually BTE (behind the |
| (thereby enlarging the outer ear) and forced into the | | | | ear) devices. The next sort is the programmable |
| inner ear. Then, all of a sudden in historical terms, along | | | | analogue hearing aid. This device is programmable for |
| came electricity and wiring and circuitry and batteries | | | | use in different predicaments and is a huge advance |
| not much more than a hundred years ago. | | | | on the simple analogue process. |
| Modern hearing aids work on much the same principle. | | | | The last category is the modern digital hearing aid. It is |
| A microphone gathers the sound, amplifies it and | | | | also the most effective and the most costly. Its |
| immediately plays it back through a loudspeaker which | | | | circuitry is capable of Digital Sound Processing or DSP. |
| is placed in or behind the ear. Owing to the level of | | | | These digital devices use many millions of sound |
| technology, the early hearing aids were big and | | | | codes to identify frequencies and then either filter |
| unsightly. The battery was the size of a house brick | | | | them out or amplify them. The difference is like going |
| and so was the amplifier. The microphone was large | | | | from vinyl records to CD's. |