Page 53

EETE OCT 2013

configuration, also plays a role in determining conversational styles. SoC-based voice triggers, as shown in figure 2, tend to suffer from the very high quiescent power overheads caused by the main central processing units (CPU) being permanently active. The battery current overheads for these solutions are typically an order of magnitude higher than those of audio hub-based solutions. Discrete solutions as shown in figure 3 frequently use different Fig. 2: SoC-based voice trigger. hardware interfaces from the main audio channels. This can sometimes lead to audio discontinuities as the management of use case transitions and noise reduction enable/disable is complicated by the different latencies and signal formats across the different integrated circuits (ICs). These discontinuities can sometimes cause conversations to be interrupted, in particular as the transition to active mode operation occurs, leading to a requirement for audible prompts which constrain conversational style. In some cases access to a limited number of microphones can also restrict usability (for instance operation with headset microphones). Ensuring a positive user experience As with all technological innovations that fundamentally is that they should become an accepted and expected feature of the next generation of mobile hardware. We will probably learn fairly quickly how to interact with a new generation of machines that respond to speech, in much the same way as we developed an intuitive familiarity with touchscreens, to the extent that touch functionality has become a standard feature of new devices hitting the market. Nevertheless, unlike older speech communication technolo- Fig. 3: Discrete voice trigger solution. Explore an incredible range of PASSIVES From industry leading brands thousands of new parts, ready to ship www.farnell.com an absolute minimum as the noise profile of the environment changes, minimising average battery currents. Alternative architectures tend to fall into two categories: discrete solutions and System-on-Chip (SoC)-based voice triggering. The power consumption profiles and user interaction styles can depend strongly on these architecture choices. Software architecture, particularly in the management of use case transitions and serial port change the way users interact with consumer devices, the true measure of success is the way the user responds to the changes expected of them. Referring to the example of touchscreens, the ultimate aim of new voice control technologies 190W x 90H (5).indd 1 09/09/2013 13:21 www.electronics-eetimes.com Electronic Engineering Times Europe October 2013 41


EETE OCT 2013
To see the actual publication please follow the link above