3.1 Digital Signal Processor
The BM83 module integrates a high-performance DSP to provide excellent voice and audio user experience. The advanced speech features, such as AEC and NR are inbuilt. To reduce nonlinear distortion and echo cancellation, an outgoing signal level to the speaker is monitored and adjusted to avoid saturation of speaker output or microphone input. Adaptive filtering is also applied to track the echo path impulse in response, to provide an echo free and full-duplex user experience.
The embedded noise reduction algorithm helps to extract clean speech signals from the noisy inputs captured by the microphones and improves communication.
In addition to NR/AEC function, audio effect functions such as Multiband Dynamic Range Compression (MB-DRC), virtual bass enhancement (VB), and audio widening (AW)), for A2DP audio streaming are also available to enhance the audio quality for various applications. For mono speaker/speakerphone and stereo headset applications, MB-DRC and VB can be enabled to have better audio clarity. For stereo speaker/speakerphone applications, in addition to MB-DRC and VB, AW can be enabled to provide better live audio effect for the users.
The following figures illustrate the signal processing flow of speakerphone applications for speech and audio signal processing.
- The DSP parameters can be configured using the Config Tool.