# Wearable Vibration Based Computer Interaction and Communication System for Deaf
## 3 Materials and Methods  
In the first phase, our wearable system was tested and applied in real-time. Our system estimates new incoming data in real time and gives information to the user immediately via vibrations. Our wearable device predicts the direction again as the system responds and redirects the user. Using this method helped find the best of the methods described in the previous section and that method was implemented. Different voices were provided from different directions to subjects and they were asked to guess the direction of each. These results were compared with real results and the level of success was determined for our wearable system. In the second phase, the system is connected to the computer and the voices and their directions were transferred to a digital environment. Data collected from four different microphones were kept in matrixes each time and thus a data pool was created. The created data passed the stages of preprocessing, feature extraction and classification, and was successful. A comparison was made with the real time application and the results were interpreted. The developed wearable system (see Figure 3) had four microphone inlets. Four microphones were required to ensure distinguishable differentiation in the four basic directions. The system was first tested using three microphones, but four were deemed necessary due to three obtaining low success rates and due to there being four main directions. They were placed to the right, left, front, and rear of the individual through the developed human-computer interface system. The experimental results showed accuracy improved if four microphones were used instead of three. Two vibration motor outlet units were used in the developed system; placing the vibration motors on the right and left fingertips permitted the indication of the direction of sound by specific vibration frequencies. The most important reason in the preference of fingertips is the high number of nerves present in the fingertips. Moreover, vibration motors placed on the fingertips are easier to use and do not disturb the individual. The developed system has four Light Emitting Diode (LED) outlets; when sound is perceived, the LED of the outlet in the perceived direction of vibration is lit. The use of both vibration and LED ensures that the user can more clearly perceive the relevant direction is perceived. We use LEDs to give a visual warning. Meanwhile, the use of four different LED lights is considered for the four different directions. If the user cannot interpret the vibrations, they can gain clarity by looking at the LEDs. The role of vibration in this study is to activate the sense of touch for hearing-impaired individuals. Through touch, hearing-impaired individuals will be able to gain understanding more easily and will have more comfort. The features of the device we have developed are; ARM-based 32-bit MCU with Flash memory. 3.6 V application supply, 72 MHz maximum frequency, 7 timers, 2 ADCs, 9 com. Interfaces. Rechargeable batteries were used for our wearable device. The batteries can work for about 10 h.  
In vibration, individuals are able to perceive the coming sound with a difference of 20 ms, and the direction of coming sound can be determined at 20 ms after giving the vibration. In other words, the individual is able to distinguish the coming sound after 20 ms.  
Vibration severities of 3 different levels were applied on the finger:  
* 0.5 V-1 V at 1 st level for perception of silent sounds
* 1 V-2 V at 2 nd level for perception of medium sounds
* 2 V-3 V at 3 rd level for the perception of loud sounds  
Here, 0.5, 1, 2 and 3 V indicate the intensity of the vibration. This means that if our system detects a loud person, it gives a stronger vibration to the perception of the user. For 50 people with normal hearing, the sound of sea or wind was provided via headphones. The reason for the choice of such sounds is that they are used in deafness tests and were recommended by the attending physician.