Headphone PHIL (Preventing Hearing Impairment/Loss) (2015)

Wearable Project


Individual class project

Skills/Software implemented: Arduino, Prototyping, Interaction Design, App development with MIT App Inventor 2

With various portable devices developed and countless of music streaming applications provided, listening to music has never been more convenient. We tend to listen to music all the time - when we are on our way to school, when we are at work, when we are exercising and even when we are falling asleep. However, most who enjoy listening to music simply indulge themselves in the melodies without paying attention to the volume level that they are hearing to. If one is actually listening to music at an inappropriate volume level for a long time, it can lead to irreversible hearing impairment in one's future.

Living in Hong Kong as a music lover myself, I realise how easy it is to raise the listening volume to an unsafe level without noticing. Everything is simply so noisy around that you can hardly enjoy listening to music without distraction; it's common for one to keep on raising the volume level until he or she can listen to the music clearly in his or her headphone. However it is hard to judge if the volume level one is listening to is safe or not objectively.

With such concern in mind, I have started to think about possibilities in helping people who would love to listen to music without worrying possible hearing loss in their future with a wearable design. It became obvious to me that the most objective judgement of safeness for the listening volume level is to detect the actual decibel (db) level coming out from the headphone. So a wearable design begins with the following idea illustrated in the sketch:

Illustration of the initial design

Illustration of the initial design

In the design I started to picture all the possible indications that will be helpful to the user in preventing listening to unsafe volume level. Immediate responses and reminders are must if the user starts to listen to an unsafe volume level. Therefore I came up with the idea of installing a vibrating motor which will be activated to warn the user in different vibrating durations for different situations. Afterwards, I have also decided to include a safety indicator on the exterior so that people around the user will be able to remind the user to tune down the volume if needed. For instance, children/ teenagers tend to listen to music with a loud volume - in this situation headphone PHIL can serve as a parental control device for parents to keep track of the volume level that their children are listening to.  Hoping that the safety indicator will provide a clear indication as well as adding attractiveness to the user, an LED ring with direct colour code to indicate the volume level has been included in the design.

In the first prototype test, the vibrating motor installed on the headphone did not work as well as I thought it would be. Test user commented that the vibrating motor in the headphone is not strong enough and therefore the user herself could not clearly tell if it was vibrating to warn the user about the listening volume level or not. After evaluation, I decided to change the indication for the user in the second prototype.

Prototyping process

Prototyping process

For the second prototype, a simple companion music app created with MIT App Inventor was included in the design. The app will read the db level from the headphone through the bluetooth module, and remind the user if the volume level is appropriate or not in two ways - 1. Activating the vibrating motor of the phone itself; 2. Text indication within the app. So now the user will be able to receive indication in the phone in various ways as well as possible reminder from others with the change in the LED ring indicator on the exterior of the headphone.

The second prototype is tested in a workshop area where a lot of drilling and cutting happen from time to time. It is common for people in the workshop area to raise the volume level of their own device so that the music will not be covered by all the noise in the workshop. The documentation of the wearable prototype - Headphone PHIL being used in the workshop area is shown in the video from the top of the page.

Hopefully every user of headphone PHIL will be able to listen to music on his or her headphone without worrying such enjoyment may lead to possible hearing impairment in their future.