**3.1.3 Sound**

Rob knows that microphones are the standard tools for acquiring sound information from the environment in a robotic platform. They can be installed in different configurations and detect/regulate sound in ways that surpass human abilities. But detecting a sound is just the starting point of a more complex challenge. Once a sound has been detected, it is time to localize the origin or source of that sound. Humans' remarkable ability to detect, localize and recognize sound can be exemplified using the *cocktail-party effect*. This term describes the ability of a person to direct his/her attention on the source of a sound amidst other sound sources which makes possible, for example, to talk to another person in a noisy, crowded party (Haykin & Chen, 2005).

It has been shown in humans that a continuous interaction between auditory and visual cues take place in the brain (Cui et al., 2008). In humanoid robots the localization of a sound source is mainly done by computing the difference in times and levels of signals arriving to the different sensors, in this case microphones (Keyrouz, 2008). Attempts to integrate sensor information from visual with auditory modalities has also been done in humanoid platforms (Ruesch et al., 2008).

Rob trusts that at least from the hardware point of view, he will not have many problems. The real challenge for the future is to improve the way different sensor modalities can be merged to replicate or surpass the abilities found in humans. However this point belongs to the *mindware* of his platform, so he will focus on working in optimized configurations of microphones.

#### **3.1.4 Odor and taste**

Rob gets a strange feeling at this point and thinks, "Should I even consider spending time thinking about a robot with these two senses? After all, robots do not need to eat anything as humans do, they just need a power cable and will have all the energy they need. And electricity has no smell, right?" But then he starts thinking in more holistic terms– maybe robots will need to somehow recognize smells and flavors; moreover, they will need to associate that information with visual, auditory and tactile cues. Otherwise it is going to be difficult, if not impossible, to interact with humans using more or less the same language. Artificial noses and "tongues" have already been developed and they are also overmatching of chemical molecules ranging from biological agents to wine and perfume. As in the case of sound, it does not seem difficult to trust that in the near future Rob will have access to a device that gives his robot information about odor and taste, at the very minimum at human levels.
