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US 12,634,620 B2Granted
Digital lavalier microphone
AssigneeSound Devices LLC
InventorMatthew G. Anderson
Life of this patent
Estimating the term…
Abstract
A lavalier microphone has improved dynamic range. The lavalier microphone incorporates a pair of microphone transducer elements into the same housing or attached housings, with one of the microphone transducer elements being more sensitive to acoustic input than the other. The voltage signals from the respective transducer elements are processed and combined, resulting in a digital output audio signal with improved signal to noise both at lower and higher input acoustic levels.
Claims23
A microphone with improved dynamic range comprising:
- a first microphone transducer element having a first sensitivity to acoustic pressure input and outputting a first voltage signal in response to acoustic pressure detected by the first microphone transducer element;
- a second microphone transducer element having a second sensitivity to acoustic pressure input and outputting a second voltage signal in response to acoustic pressure by the second microphone transducer element;
- wherein the first sensitivity to acoustic pressure is greater than the second sensitivity to acoustic pressure;
- means for amplifying and digitizing the first voltage signal to generate a first digital signal;
- means for amplifying and digitizing the second voltage signal to generate a second digital signal;
- an internal digital processor that receives the first digital signal and the second digital signal and outputs a digital audio output signal with improved signal to noise both at lower and higher input acoustic levels, said internal digital processor providing:
- a first data buffer for storing frames of data for the first digital signal, and a second data buffer for storing frames of data for the second digital signal,
- means for applying a window function that overlaps in time to the frames of data to generate windowed data packets corresponding to each of the first and the second microphone transducer elements, and
- a combiner configured to select a windowed data packet for one of the microphone transducer elements and sequentially combine the selected data packets to construct the digital audio output signal;
- and
- means for providing DC power to the internal digital processor, the first microphone transducer element, the second microphone transducer element, means for amplifying and digitizing the first voltage signal and means for amplifying and digitizing the second voltage signal;
- wherein the first and second microphone transducer elements, said means for amplifying and digitizing the first voltage signal to generate a first digital signal, said means for amplifying and digitizing the second voltage signal to generate a second digital signal, and the internal digital processor are located within a common housing or attached housings.
9 more elements
A method of generating a digital audio output signal with improved signal to noise both at lower and higher input acoustic levels comprising the steps of:
- providing a first microphone transducer element having a first sensitivity to acoustic pressure input;
- providing a second microphone transducer element having a second sensitivity to acoustic pressure input, wherein the first sensitivity to acoustic pressure is greater than the second sensitivity to acoustic pressure;
- providing a first impedance converter having a first junction field-effect transistor (JFET);
- providing a second impedance converter having a second junction field-effect transistor (JFET);
- providing a first pre-amplifier and a second pre-amplifier;
- providing a first analog to digital converter and a second analog to digital converter;
- providing an internal digital processor, wherein the first and second microphone transducer elements, the first and second impedance converters, the first and second pre-amplifiers, the first and second analog-to-digital converters and the internal digital processor are located within a common housing or attached housings;
- supplying a biasing voltage to the first microphone transducer element and outputting a first low voltage signal in response to acoustic pressure detected by the first microphone transducer element;
- supplying a biasing voltage to the second microphone transducer element outputting a second low voltage signal in response to acoustic pressure by the second microphone transducer element;
- inputting the first low voltage signal to the first impedance converter and outputting a first amplified, low impedance voltage signal from the impedance converter;
- inputting the second low voltage signal to the second impedance converter and outputting the second amplified, low impedance voltage signal from the impedance converter;
- inputting the first amplified, low impedance voltage signal to the first preamplifier and outputting a first amplified voltage signal;
- inputting the second amplified, low impedance voltage signal to the second preamplifier and outputting a second amplified voltage signal;
- inputting the first amplified voltage signal into the first analog-to-digital converter to generate a first digital signal;
- inputting the second amplified voltage signal into the second analog-to-digital converter to generate a second digital signal;
- inputting the first digital signal and the second digital signal to the internal digital processor;
- and
- combining the first and second digital signals or signals derived from the first and second digital signals to generate a digital audio output signal with improved signal to noise both at lower and higher input acoustic levels.
15 more elements
Dependencies are inferred from the claim text.