Wearable devices such as, smart watches and fall assist devices, need to include Voice Quality Enhancement software as part of the product design. The reasons for this are clear when you review the high-level audio system requirements:
- Requirement 1: The device must have hands-free full duplex audio capabilities.
- Requirement 2: The audio of the user must contain minimal amounts of background noise and acoustic echoes.
- Requirement 3: The loudspeaker audio must achieve sufficient audio signal levels with minimal signal distortions.
- Requirement 4: The device must be energy efficient.
Requirements 1 and 2 dictates the use of an Acoustic Echo Cancellation (AEC) algorithm. The AEC software will resolve the acoustic coupling that occurs between the loudspeaker and microphone during full duplex operation.
Noise Reduction software will help meet requirement 2. Requirement 4 puts some restrictions on the noise reduction algorithm design. At minimum, a single channel noise reduction algorithm which performs spectral noise reduction must be included. Multi-microphone noise reduction algorithms such as, acoustic beamforming and noise cancellation potentially can be included. Utilizing two microphones balances the tradeoff between power consumption and noise reduction capabilities.
For Requirement 3, Automatic Gain Control (AGC) will help to achieve consistent audio signal levels. When the incoming signal is too quiet, the user will be tempted to increase the signal levels, too much gain in the analog and digital domains can cause distortion. Software AGC will dynamically adjusts the digital gain so the incoming signal achieves the appropriate signal level for the audio hardware.
Therefore, a Voice Quality Enhancement package must include AEC, Noise Reduction and Automatic Gain Control modules to meet the requirements of wearable devices. Please contact us to learn more about our VQE solutions.