Once again a successful meeting was held with more than 40 visitors joining the factory tour and the presentations at Phonak AG in Stäfa.

First the visitors were split in two groups and guided through the high-tech factory producing hearing aids in many variations. From the individual production of paediatric ear-canal inserts over robot-operated plastic moulding machines to very fine pitch mechanical and soldering workplaces, the company was able to show a high amount of know-how in their business. The remarkable layout of the building has also to be mentioned, where practically no doors exist and easy communication is possible between people of all departments.

Qualified personnel gave special explanations for certain design or manufacturing processes at various stages on the tour. After these very interesting one and a half hours, the two organizations SGA-SSA and AES welcomed the participants to the talks. Beat Hohmann started with his speech about music-induced hearing loss. First an overview was given on the causes and effects of hearing loss, like the standard hearing curves and the physiognomy of the human ear. Then the situation of Swiss laws concerning noise at working places were addressed and explained that for a 40h-week the average noise should not be higher than 87dB(A). His institution has worked on an interesting issue recently, namely that professional musicians often suffer from levels higher than 87dB(A) per working week and therefore show hearing losses. So for some musicians it is even recommended to wear ear protection during their "work".

A presentation of a study on the behaviour of young people listening to modern music completed this interesting speech.After this, Dr. Volker Kühnel from Phonak gave a speech "Psychology and audiology in normal and hearing-impaired persons". Rounding up the explanations about the physiognomy of the human ear, one interesting point was explained, that hearing damage affects not only the levels but also the ability to discriminate frequencies which makes it impossible to correct the damage back to 100 percent, as is possible with glasses for sight.

Today's hearing aids are therefore highly sophisticated signal processors, which do multiband dynamics processing as well as adaptive focusing to sound sources using multiple microphones. Various tools have been developed by Phonak to register the ear curves of hearing impaired people at different levels and to program the hearing-aids accordingly. Some design aspects were also explained, like power considerations, since amplifications of up to 90dB have to be supplied by 0.9 to 1.3 Volts at less than 2mW.

Further features are integrated, such as reception of FM signals from dedicated microphone transmitters as well as the ability to use mobile telephones with hearing aids. A dinner at the restaurant Sonne in Stäfa finished this very interesting meeting. The Swiss AES section and SGA-SSA want to thank Phonak AG again for their efforts and hospitality.