Hearing aids user interface timeline

Gemba is a Japanese term, which in the QFD Voice of Customer context means to visit the place where the product will be used. The acclaim is that the first-hand experience of customer needs and wants in the use journey, when combined with the product designer’s technical skills and knowledge, represents an opportunity for creating value beyond what could otherwise be achieved.

Philosopher Immanuel Kant (1724-1804) argued that “using reason without applying it to experience only leads to theoretical illusion” and that “we see things not as they are, but we instead see things as we are”. The designer sees the design problem in his or her individual way, which if done distantly can too easily differ from that of real customers. It is therefore important that product designers meet customers in person, to establish empathy and truly experience the use environment.

The above illustration shows the progression in hearing aids user interface designs. It represents, in my view, an example of how product designers have failed to understand their customers. Had the designers spent just a small amount of time observing the average hearing owner using their products, then I don’t believe they would have come up with the 2007 and 2014 ideas. Here is why:

The year 2000 hearing aid had a mechanical dial for controlling the sound loudness (volume) and a 3-position mechanical toggle for switching between ‘off’ and 2 listening profiles (programmes). Both interface features were tactile and recognisable. Their downside were the cost of manufacturing and a minor reliability issue (generally good durability, but could occasionally go wrong). Their nature of protruding through the hearing aid casing would leave a small air gap, through which water and sweat could ingress – but the circuitry inside was normally coated to prevent this from becoming a problem.

The ‘modernised’ year 2007 hearing aid replaced the rotary mechanical interfaces with a simpler up-down push buttons arrangement. The buttons have a lower manufacturing cost and (slightly) improve on reliability. The design also allows for more programmes to be configured, typically up to 4 different listening situations (e.g. one-to-one, noisy environment, music listening, restaurant). A short push on the up button increases the volume. A long push on the up button steps to the next listening program. The down button performs the reverse functions. Simple, for a 30-something old design engineer. The issue, however, is that hearing loss is mostly age related and it affects relatively few in their 30’s. Many customers are in their 80’s and in a natural stage of tactile and cognitive decline. Users often no longer have the cognitive capacity to remember the difference between a short and long push. A significant number of users cannot recognise the push buttons by their fingertip and they do also not always know if they are pushing the up or down button. The ear deforms when pressing on the back of the ear, which can cause the ear insert to pop slightly out and create a feedback whistling noise from the hearing aid. Lastly, many users find it impossibly hard to learn the differences between the 4 programmes settings for different listening situations. As result, most hearing aids are set sub-optimally.

The ‘state-of-the-art’ year 2014 hearing aid introduces a touch-sensitive strip for user interface. This has yet lower manufacturing costs and entirely seals the casing top surface to prevent moisture ingress (of which the latter practically solves a non-problem). Brushing up or down on the strip adjusts the volume. Tapping the strip advances to the next listening programme, which when reaching the last programme jumps back to the first. When launching the product at an international trade fair, the manufacturer’s marketing team tweeted: “We can see the fear in the eyes of our competitors”.  They genuinely believed in its pending success. However, the concept soon faded away in the market. Again, because the designer lacked the insight into the customer journey. Had they observed how the average 80-year old operate their hearing aid they would have noticed the user first fumbles on the side of the head to locate the ear and then the hearing aid. Once the user has located the hearing aid, he or she then tends to hold on to it (touching) while thinking through what to do next. By time the user is ready to operate the user interface, a whole raft of uncontrolled mal-adjustments have already happened. The anxiety associated with getting it wrong causes users to avoid adjusting their hearing aids.

Hearing aid sound processing technology and visual design have improved leaps and bounds over the last 20 years. Yet, market data from the UK’s international manufacturing association shows that the percentage of hearing aids returned for refunds, because customers were not entirely satisfied or do not get on with them, has increased markedly over the same period. Adding features and gizmos may help selling the product (at a higher price); but unless the customer is able to use them then it makes no difference to satisfaction and success. I have spoken to healthcare professionals who tell about patients frequently being reluctant to give up their old model, for a so called ‘upgrade’. Design is of course a subjective topic, but I believe to recognise the hearing aid concept that offers the best use experience. As it happens, its manufacturer also has the biggest market share.

You designers, you must occasionally get out of the development lab and into the real world.

If you can afford to, then do what one mobile phone manufacturer did. Tasked with developing a new model, the design team first went on a world trip, meeting people in the streets, side-streets and other places where they use phones. They visited Moscow, Tokyo, Sao Paulo and Los Angeles, just to reach users and observe and talk about how they use phones. The length you go to in this exercise depends of course on the product, and budget. The hearing aid designer could have learned sufficiently about user interface design by simply bringing a pack of good biscuits to a 3-hour visit at an old people’s home.