Synchronization of Buffered Data in Multiple Microphones
First Claim
1. A method, the method comprising:
- receiving first analog signals from a first microphone, converting the first analog signals into first pulse code modulation (PCM) digital data and storing the first PCM digital data in a first buffer using a first microphone internal clock;
receiving a second analog signals from a second microphone according to a second microphone internal clock, converting the second analog signal into second PCM digital data and storing the second PCM digital data in a second buffer;
wherein the first PCM digital data in the first buffer is not synchronized in real time with the second PCM digital data in the second buffer due to the absence of a common clock or other synchronizing signal between the first microphone and the second microphone;
determining whether voice activity has occurred at a first acoustic activity detect (AAD) module based upon the first PCM digital data, and when voice activity is determined, transmitting a voice activity detect signal to an external processor, the external processor responsively providing an exterior clock signal upon receiving the voice activity detect signal;
up-converting the first PCM digital data into first pulse density modulation (PDM) data and the second PCM digital data into second PDM data based upon the exterior clock signal to eliminate a lack of synchronization or time uncertainty between the first PCM data and the second PCM data.
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Accused Products
Abstract
First analog signals are received from a first microphone and converted into first pulse code modulation (PCM) digital data and stored in a first buffer using a first microphone internal clock. Second analog signals are received from a second microphone according to a second microphone internal clock, converted into second PCM digital data and stored the second PCM digital data in a second buffer. The first PCM digital data in the first buffer is not synchronized in real time with the second PCM digital data in the second buffer due to the absence of a common clock or other synchronizing signal between the first microphone and the second microphone. A determination is made as to whether voice activity has occurred at a first acoustic activity detect (AAD) module based upon the first PCM digital data, and when voice activity is determined, a voice activity detect signal is transmitted to an external processor. The external processor responsively provided an exterior clock signal upon receiving the voice activity detect signal. The first PCM digital data is up-converted into first pulse density modulation (PDM) data and the second PCM digital data into second PDM data based upon the exterior clock signal to eliminate a lack of synchronization or time uncertainty between the first PCM data and the second PCM data.
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Citations
14 Claims
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1. A method, the method comprising:
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receiving first analog signals from a first microphone, converting the first analog signals into first pulse code modulation (PCM) digital data and storing the first PCM digital data in a first buffer using a first microphone internal clock; receiving a second analog signals from a second microphone according to a second microphone internal clock, converting the second analog signal into second PCM digital data and storing the second PCM digital data in a second buffer; wherein the first PCM digital data in the first buffer is not synchronized in real time with the second PCM digital data in the second buffer due to the absence of a common clock or other synchronizing signal between the first microphone and the second microphone; determining whether voice activity has occurred at a first acoustic activity detect (AAD) module based upon the first PCM digital data, and when voice activity is determined, transmitting a voice activity detect signal to an external processor, the external processor responsively providing an exterior clock signal upon receiving the voice activity detect signal; up-converting the first PCM digital data into first pulse density modulation (PDM) data and the second PCM digital data into second PDM data based upon the exterior clock signal to eliminate a lack of synchronization or time uncertainty between the first PCM data and the second PCM data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus, the apparatus comprising:
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a first buffer coupled to an external processor; a second buffer coupled to the external processor; a first analog-to-digital converter coupled to the first buffer, the first analog-to-digital converter configured to receive first analog signals from a first microphone, convert the first analog signals into first pulse code modulation (PCM) digital data and store the first pulse code modulation (PCM) digital data in a first buffer; a first acoustic activity detect (AAD) module coupled to the first analog-to-digital converter, the first acoustic activity detect module configured to determine whether voice activity has occurred based upon the first pulse code modulation (PCM) digital data, and when voice activity is determined, transmit a voice activity detect signal to the external processor, the external processor responsively providing an exterior clock signal upon receiving the voice activity detect signal; a second analog-to-digital converter coupled to the second buffer, the second analog-to-digital converter configured to receive a second analog signals from a second microphone according to the exterior clock signal, convert the second analog signals into second pulse code modulation (PCM) digital data and store the second digital data in a second buffer; wherein the first PCM digital data in the first buffer is not synchronized in real time with the second PCM digital data in the second buffer; wherein the first buffer, the first analog-to-digital converter, and the first acoustic activity detect module are disposed at a first microphone, and wherein the second buffer and the second analog-to-digital converter are disposed at a second microphone; wherein a first up-converter or interpolator is coupled to the first buffer, and a second up-converter or interpolator is coupled to the second buffer, the first up-converter and the second up-converter are configured to up-convert the first PCM digital data into first pulse density modulation (PDM) data and up-convert the second PCM digital data into second pulse density modulation (PDM) data based upon the exterior clock signal to eliminate a lack of synchronization or time uncertainty between the first PCM digital data in the first buffer and the second PCM digital data in the second buffer; wherein the first analog-to-digital converter, the first buffer, the first acoustic activity detect module, and the first up-converter or interpolator are disposed at a first microphone, and wherein the second analog-to-digital converter, the second buffer and the second up-converter or interpolator are disposed at a second microphone. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification