# Voice Assistant Application for Avoiding Sedentarism in Elderly People Based on IoT Technologies
## 2 Background
### Voice Assistants  
A voice assistant (VA), also known as a kind of intelligent personal assistant, is an end-user interface with verbal skills. A VA can talk to and understand users by using different kinds of artificial intelligence techniques such as speech recognition, natural language processing, dialogue systems, and speech synthesis. The communication between the VA and the user is bidirectional; however, the user is the one that starts the conversation by asking the VA to perform an action. The VA uses artificial intelligence techniques to understand the received information and perform the action if possible. The actionusually implies a response (answer) from the VA. According to the study developed by [PERSON] et al. (2019), VAs have a general architecture, which is summarized in the Figure 1. This shows the functionality and different techniques used by VAs in a normal conversation.  
The communication process starts with the user pressing a button of the VA or verbally via the pronunciation of a keyword that wakes up the VA device. The VA uses speech recognition techniques to identify the keyword and begins the conversation by waiting to receive an action or command from the user.  
Once the conversation starts, the user pronounces a phrase containing the command s/he wants to obtain from the VA. Speech recognition techniques are used by the VA to transform speech to text; this text is analyzed with Natural Language Processing (NLP) techniques. This phase of the process tries to identify in the user's sentence the action requested; the techniques also use the current context of the conversation to increase its accuracy. If the action requested is not available or if the semantics of the phrase have not been extracted correctly, the VA will communicate the result to the user using text-to-speech techniques (TTS). On the other hand, if the semantic interpretation of the phrase matches any available action, the VA will execute that action and will answer the user by TTS.  
Actions that cannot be performed by the basic functionality of the VA can be performed by the use of multimedia services or external calls, invoking third-party software agents (e.g., Google Actions or Alexa Skills), and even interacting with home automation and Internet of Things (IoT) platforms by acting on the devices of those platforms or retrieving information from them.  
There are a huge variety of actions that the VA can perform under request. This factor has led to their increasingly widespread use ([PERSON] et al., 2019). The scientific world has increased its interest in the application of VAs in older adults' home environments in recent years; therefore, some of the more recent works on VAs are described below.  
Several studies like [PERSON] et al. (2019) or the study developed by the Front Porch Center for Innovation and Wellbeing (FPCIW) ([PERSON] et al., 2019) measure the satisfaction of elderly users who have used Google Home and Amazon Echo via surveys. Other works, such as [PERSON] et al. (2019), examined the main functionalities of several assistants to assist older people; they conclude that there is still work to do to improve the communication between VAs and the elderly.  
Figure 1: Architecture of Voice Assistants.  
Hence, it is crucial to research how to integrate VAs in the daily life and routines of elderly people, transforming the VAs into useful tools and introducing digital devices and ICTs in this kind of population sector.  
It is worth mentioning how the digital divide issue related to the lack of digital skills can be addressed with VAs [23]. Nevertheless, these technologies require an ICT infrastructure in rural areas to function; without these structures, the citizens cannot take full advantage of VAs. Consequently, initiatives such as WiFi4 EU [24] and local policies to provide infrastructure in these areas are essential.