Microphone circuit assembly and system with speech recognition

A system, comprising:

• a buffer to store samples representing an input audio signal,
• a speech feature extractor having an input for samples from the buffer,
• a speech vocabulary storing data representing a predetermined set of speech elements, and
• a controller comprising a decision circuit to generate a wake up signal in response to a match between speech features output by the extractor and the stored speech elements, wherein the controller is configured to output a wake up signal indicating the match and to output samples received subsequent to the samples stored in the buffer corresponding to the match.

A non-transitory computer readable medium storing program instructions that, when executed by a processing device, causes the device to:

• buffer input audio samples,
• perform speech recognition on the buffered audio samples using a vocabulary as a reference, and
• when the speech recognition identifies a recognized speech element, generating a wake up command indicating a match;
• wherein the instructions further cause the device to output the wake up command and to output audio samples received subsequent to the buffered audio samples that correspond to the recognized speech element.

A method, comprising:

• receiving a digital audio signal;
• buffering audio samples from the received digital audio signal;
• performing speech recognition on the buffered audio samples, using a locally-stored vocabulary as a reference, to recognize a target word or target phrase in the buffered audio samples;
• and
• when the speech recognition identifies the target word or target phrase in the buffered audio samples, outputting a wake up signal indicating a recognition match and outputting audio samples received subsequent to the buffered samples corresponding to the recognition match;
• wherein at least one of the receiving, the buffering, the performing, and the outputting is performed at least in part by a first processor circuit.

A mobile system for speech recognition, the system comprising:

• a buffer circuit configured to store audio samples from an input audio signal;
• a memory circuit including speech data representing a target word or target phrase;
• a speech feature extractor circuit configured to receive audio samples from the buffer circuit and output corresponding speech features;
• and
• a controller circuit configured to generate and output a wake up signal when the speech features output by the extractor circuit correspond to the speech data representing the target word or target phrase, and the controller circuit is further configured to output audio samples received subsequent to the stored audio samples corresponding to the target word or target phrase.