Overview

DSP Concepts proprietary Quiescent Sound detector. Version 1.

Discussion

DSP Concepts proprietary Quiescent Sound Detector module. This module analyzes the incoming audio stream and determines if there is "interesting" sound which should trigger the rest of the system to wake up. The module is typically used to deactivate processing when there is no sound present.

The module operates on any block size and any number of channels. The module has a single sample Boolean output which indicates whether any sound has been detected. When the input wire has multiple channels, the module looks at the data on all channels to determine if the system should wake up.

The module has three tunable parameters. If the RMS level of the input signal is above snrThreshold, then the system wakes up. Otherwise, if the signal is below snrThreshold, if the instantaneous level is snrThreshold above the average level, then it will wake up. Both noiseFloorThreshold and snrThreshold are in units of dB.

Type Definition

typedef struct _ModuleQSDv1
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 noiseFloorThreshold;                  // Any signals above this level trigger detector.
    FLOAT32 snrThreshold;                         // dB above background noise floor to trigger.
    void * QSDptr;                                // Pointer to dspc_qsd structure
} ModuleQSDv1Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
noiseFloorThreshold	float	parameter	0	-60	-80:1:0	dB
snrThreshold	float	parameter	0	6	0:1:20	dB
QSDptr	void *	state	1		Unrestricted

Pins

Input Pins

Name: in

Description: Audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: int

MATLAB Usage

File Name: qsd_v1_module.m

 M = qsd_v1_module(NAME)
 Quiescent sound detector module.  This module can be used as a sound
 detector to wake up other parts of a system.  Arguments:
   NAME - name of the module