Speech recognition
View Patent ↗A speech recognition system comprises: an input, for receiving an input signal from at least one microphone; a first buffer, for storing the input signal; a noise reduction block, for receiving the input signal and generating a noise reduced input signal; a speech recognition engine, for receiving either the input signal output from the first buffer or the noise reduced input signal from the noise reduction block; and a selection circuit for directing either the input signal output from the first buffer or the noise reduced input signal from the noise reduction block to the speech recognition engine.
1. A speech processing system comprising;
an input for receiving an input signal from at least one microphone;
a first signal path for connecting the input to an output;
a second signal path for connecting the input to the output;
selection circuitry for selecting either the first signal path or the second signal path for carrying the input signal from the input to the output; wherein:
the first signal path contains a first buffer for storing the input signal;
the second signal path contains a noise reduction block for receiving the input signal and supplying a noise reduced signal to the output, and a second buffer; wherein:
the second buffer imparts a delay in the second signal path such that the noise reduced signal is substantially time-aligned with the output of the first buffer; and
a signal activity detection block for detecting if the input signal contains speech, wherein the first buffer comprises:
a first part which is continuously buffering; and
a second part which only starts buffering after the signal activity detection block detects that the input signal contains speech.
2. An integrated circuit comprising a speech recognition system as claimed in claim 1 .
3. A communications device comprising an integrated circuit as claimed in claim 2 .
4. A method for speech recognition comprising:
receiving an input signal from at least one microphone;
selecting either a first signal path or a second signal path for carrying the input signal to the output; wherein:
the first signal path contains a first buffer for storing the input signal; and
the second signal path contains a noise reduction block for receiving the input signal and supplying a noise reduced signal to the output, and a second buffer; wherein:
the second buffer imparts a delay in the second signal path such that the noise reduced signal is substantially time-aligned with the output of the first buffer; and
detecting if the input signal contains speech, wherein the first buffer comprises:
a first part which is continuously buffering; and
a second part which only starts buffering after the signal activity detection block detects that the input signal contains speech.