From brass ear trumpets to cochlear implants, hearing devices have come a very long way. Spanish manufacturer GAES has been innovating for the last 60 years or so, and during that time it has applied all available technologies to make hearing aids smaller, less obtrusive and more effective.

Thanks to rising living standards, people in developed nations are living longer, which is a good thing, of course. However, ageing creates problems, with hearing loss and preventable blindness just two of the world’s greatest health-care challenges; they also present huge commercial opportunities.

In India, for example, Appasamy is using Haas CNC machine tools (www.haascnc.com) to make intra-ocular lenses for millions of patients suffering from cataracts, glaucoma and similar eye conditions. In Barcelona, hearing-aid manufacturer GAES recently bought a Haas VF-2SS CNC machining centre, which it uses to make moulds and dies for its bespoke products.

GAES began almost by chance in 1949 after its founder — Juan Gassó — returned from a trip to London with a primitive hearing aid that he had brought for a family friend. Inspired by the difference that such devices could make, and fascinated by what at the time was cutting-edge technology, Mr Gassó began a business to import and distribute them. In those early years he did his sales rounds on a green 1953 Ossa motorcycle, demonstrating his products to patients and potential customers the length and breadth of Spain.

Business was brisk and in 1958 Mr Gassó established Microson SA, the first and only manufacturer of hearing aids in the country. As part of GAES, Microson was created to provide users with pocket-size analogue (transistor-based) devices.

Nowadays, the size and output of the business belies its humble origins; its five-floor factory is located at a busy traffic junction in the ‘22@’ area of Barcelona. The new headquarters was opened in 2010 and dedicated to its founder.

In the window of the office foyer is his Ossa motorcycle, now restored; a long glass display on an adjacent wall shows the evolution of the GAES product over the decades. The global market for hearing aids is worth $5.4 billion annually, and GAES is the leading hearing-aid company in Spain, employing 130 people and producing more than 50,000 hearing aids every year.

‘Tailor-made’

Microson has a production target for its ‘high-volume’ products of 50-60 units a day. The Haas machining centre, however, is used in the production of bespoke devices that fit users’ exact ear dimensions. Sergio Pavon, R&D technical assistant, says: “The process starts when one of our hearing centres sends us a patient’s ear-print. This is a 3-D negative of the ear canal, created using a type of resin. We scan the negative form and obtain a 3-D file in our CAD/CAM system, which we then use to program the Haas machine.

"Now that we have the Haas, we can go from order to delivery of custom devices within 3-4 days; it has also allowed us to take control of the entire manufacturing process. Moreover, as well as reducing the time required to make a new part, the Haas has also ensured better product uniformity.”

Although the VF2-SS is used for many day-to-day component-machining tasks, its main use is the machining of moulds. These in turn are used to produce very delicate and small parts used within the company’s hearing devices, by means of conventional injection moulding and special heat-less ultrasound injection machines.

The ultrasound method was introduced initially to produce a tiny plastic circular part, which has a membrane mesh that stretches across the microphone part of the hearing aid to protect against wind, water and dust.

Mr Pavon says: “The component demands the use of a very expensive plastic. It must be non-allergenic and comply with certain health-industry directives. Conventional moulding was leading to high scrap rates, as the part would be damaged by the inherent heat of the process.”

With the company’s specially designed ultrasound machine, there is no heat. Instead, an electrode vibrates 30,000 times every second to liquify the resin. The company uses this machine to make the inner ear canal fitting and filter.

The electrodes produced for the ultrasound machine are also machined using the VF2-SS, which runs largely unsupervised across two shifts every day.

Machine selection

Explaining the process that the company used to select the right make and model of machine from a number of different options, machine shop manager Ivan Jimenez says: “When looking for a new machine, the first thing we do is complete a verification report in which the supplier — in this case, Haas — fills in a series of requirements with which we need the machine to comply.

"Using this evaluation method, we complete a spreadsheet in which we start to award marks to each machine. We continue this process until we are satisfied that the decision for purchase is based on completely objective factors such as spindle speed, power, accuracy and repeatability, rather than subjective factors such as visual appearance.”

Lluis Gómez, technical director of Microson, adds: “Actually, it was quite a hard decision. Ultimately, it was based on the relationship of price and quality, although the delivery lead time was also very important. The Haas technology has allowed us to shorten the time required to machine delicate and high-precision parts.”

GAES founder Juan Gassó passed away in 2008. By then, the company had opened more than 500 hearing centres world-wide; it now has offices in Portugal, Turkey, Chile and Argentina — and more than 500,000 customers. That is an impressive legacy for a salesman who started his business from the back of a little green motorcycle.