This prototyped uses the interaction of using audio onsets (claps, clicks etc) as a mode of input. Increasing the number by one with each clap makes sense, but needs some way of making up for mistakes. The current method is to use a double clap to decrease by one. The downside of this is that a delay needs to be introduced, as we have to wait to know whether it was a single or double clap. This delay means that for single claps, it is not as satisfyingly instant.

After experimenting with the timing, 200 milliseconds (0.2 seconds) was found to be long enough to reliably double clap, but the delay is noticeable. Dropping down to 150ms makes it difficult and unreliable to perform a double. This is probably a parameter that would have to be tuned (like double click speed on a computer) for different users’ abilities. An older user might have trouble at 200ms. 150ms was also definitely too short a window to perform a double by clicking the fingers on one hand.

Triple triggering is used to reset the counter to zero. This was borne out of necessity while making the video, it was getting too annoying to reset it via code. Prototyping is key!

This interaction is particularly suited to situations when occupied by another activity, but needing to count something, e.g. counting the number of reps of an exercise, or the number of passes in a football match. As the user’s attention may be elsewhere, it may be worth having a form of feedback, such as the computer announcing the current value whenever it is changed. This might be annoying when counting a lot of events, so every 5/10/N reps would be a nice option.

This interaction is somewhat similar to a bouncer’s “clicker”, which has simple and tactile enough controls to be used without looking. This approach has the upside of no device needing to be held, so can be triggered in a variety of ways: clapping the hands, making noises with the mouth, hitting an object. It is also really suited to counting activities that inherently make noise, like how many times someone hits the side of their mug with the spoon when stirring their tea. A definite weakness is the susceptibility to noise, in a noisy environment it become unusable. It’s also not good for making larger increments quickly.