SSL (Sound Source Localization)

Supported ICs

Overview

Sound source localization if one of the AFE’s features, to calculate the direction of the speaker. Requires two or more microphones.

In products requiring speaker localization (e.g., robots, smart toys), the SSL module can be used alongside KWS to output the speaker’s direction angle after each wake-up event.

Algorithm Description

  • Dual Mic

    • Output angle range: 0° ~ 180°

    • The microphone positions and corresponding angles:

      ../../../_images/mic_array_position_2mic.svg

  • Three Mic

    • Output angle range: 0° ~ 360°

    • The microphone positions corresponding to the mic data should be arranged counterclockwise.** The microphone positions and corresponding angles:

      ../../../_images/mic_array_position_3mic.svg

Configurations

The complete AFE configuration file is located at ${aivoice_lib_dir}/include/aivoice_afe_config.h. The SSL-related configurations include:

// AFE common parameter
afe_mic_geometry_e  mic_array;          // microphone array. Make sure to choose the matched resource library

afe_mode_e afe_mode;                    // AFE mode, for ASR or voice communication.
bool enable_ssl;                        // SSL(Sound Source Localization) module switch.

// SSL module parameter
float ssl_resolution;                   // SSL solution(degree)
int ssl_min_hz;                         // minimum frequency(Hz) of SSL module.
int ssl_max_hz;                         // maximum frequency(Hz) of SSL module.