Intercom apparatus for integrating disparate audio sources for use in light aircraft or similar high noise environments

• US 4,941,187 A
• Filed: 01/19/1989
• Issued: 07/10/1990
• Est. Priority Date: 02/03/1984
• Status: Expired due to Term

• Current Assignee: Northern Airborne Technology Ltd. (Cobham PLC)
• Original Assignee: Robert W. Slater
• Inventors: Slater, Robert W.
• Primary Examiner(s): Isen, Forester W.
• Application Number:
  US07/300,166
• Time in Patent Office: 537 Days
• Field of Search: 381/77, 381/82, 381/110, 381/86, 381/92, 381/94, 381/74, 379/175
• US Class Current: 381/86
• CPC Class Codes: H04M 9/001 Two-way communication systems between a limited number of parties
• CPC Class Codes: H04R 2420/01 Input selection or mixing for amplifiers or loudspeakers

Abstract

Intercom apparatus having stereo amplifiers adapted for connection to one or more headsets. A plurality of headset output and microphone input connections are provided. Each microphone input includes a separate microphone switch and audio detector whereby only microphone inputs having voice audio thereon are activated. Stereo entertainment and aircraft radio audio inputs are provided. An aircraft radio audio detector is interfaced, along with the various microphone audio detectors, to entertainment partial mute circuitry whereby the presence of a voice or radio audio signal lowers the amplitude of the entertainment input. Microphone and aircraft radio partial mute circuitry are interfaced through a priority selector switch with respective microphone and radio signal detectors. The priority selector switch is a two position, center off arrangement whereby, in one position, aircraft radio signals partially mute microphone signals and in the second position microphone signals partially mute aircraft radio signals. In the center off position no cross muting occurs and the respective signals sum in conventional manner.

Claims

1. Apparatus for integrating disparate audio sources for use in light aircraft or in other high noise environments comprising unitary driver means for generating a composite output signal representative of a driver input signal, audio output means associated with the output of the driver means for connection of a plurality of remote headsets whereby a substantially identical composite output signal will be present at all of the headsets without regard to the source of audio comprising said composite output signal;

audio signal summation means operatively connected to the driver input having a plurality of audio inputs for connection of remote microphones, each remote microphone being associated with and proximate to a headset whereby an occupant of the aircraft may speak into a microphone and listen to the composite output signal, including the voice audio of said occupant, through the associated headset, said audio summation means funtioning to combine the respective audio inputs to form a single composite signal;

each summation means audio input including an associated audio switch means, audio detector means, and audio input means for connection of an audio input signal thereto;

each audio switch means connected in series between the associated summation means audio input and the audio input means, and each audio switch means having a gate means whereby the switch means may be selectively controlled to a first closed-circuit condition whereby an audio input signal at the associated audio input means is substantially connected to the summation means audio input and a second open-circuit condition whereby an audio input signal at the associated audio input means is substantially removed from said audio input;

each audio signal detector means being operatively connected to the gate means of the associated switch means and to the associated audio input means, each detector means being unresponsive to audio input signals on other than the associated audio input means, whereby the detector means controls the associated switch means into the first closed-circuit condition whenever an audio input signal of predetermined amplitude is present at the associated audio input means without regard to the input signal condition on any other audio input means and into the second open-circuit condition following a predetermined interval in which an audio input signal at the associated audio input means has not exceeded the predetermined amplitude whereby only audio input signals having a predetermined amplitude contribute to the driver means output signal thereby improving the audio quality by eliminating noise present on unused audio signal inputs.

2. Apparatus for integrating disparate audio sources, including microphone signals and other non-microphone input signals, for use in light aircraft or in other high noise environments comprising unitary driver means for generating a composite output signal representative of a driver input signal, audio output means associated with the output of the driver means for connection of a plurality of remote sound transducer means thereto whereby a substantially identical composite output signal will be present at all of the remote sound transducer means without regard to the source of audio comprising said composite output signal;

audio signal summation means operatively connected to the driver input having microphone input means and other input means, said audio summation means functioning to combine respective microphone and other input means to form a single composite signal;

means for interconnecting microphone signals to the microphone input means in response to predetermined minimum microphone signal levels, said interconnecting means including switch means and microphone signal detector means;

switchable mute means for interconnecting said other non-microphone input signals to the other input means, the mute means operatively connected to the microphone signal detector means such that the amplitude of the other input signals interconnected to the other input means is lowered by a predetermined non-zero fractional degree in response to predetermined minimum microphone signal levels whereby fractionally muting the other signal enhances microphone signal intelligibility without appreciably interrupting the continuity of said other signals.

3. The apparatus for integrating disparate audio sources of claim 2, the disparate audio sources including radio signals, wherein the audio signal summation means includes radio signal input means and including radio signal detector means operatively connected to the other signal mute means whereby the amplitude of the other signal interconnected to the other signal input means is lowered by a predetermined non-zero fractional degree in response to detected radio signals or predetermined minimum microphone signal levels whereby fractionally muting the other signal enhances microphone and radio signal intelligibility without appreciably interrupting the continuity of said other signals.

4. Apparatus for integrating disparate audio sources for use in light aircraft or in other high noise environments comprising unitary driver means with a driver input for generating a composite output signal representative of a driver input signal, audio output means associated with the output of the driver means for connection of a plurality of remote sound transducer means thereto whereby a substantially identical composite output signal will be present at all of the remote sound transducer means without regard to the source of audio comprising said composite output signal;

audio signal summation means operatively connected to the driver input having microphone input means and radio input means, said audio summation means functioning to combine outputs from the microphone input and radio input means to form a single composite signal;

means for interconnecting microphone signals to the microphone input means in response to predetermined minimum microphone signal levels, said interconnecting means including microphone switch means and microphone signal detector means;

radio signal detector means;

microphone mute means for lowering the microphone input signal by a predetermined first non-zero fractional degree;

radio mute means for lowering a radio input signal at the radio input means by a predetermined second non-zero fractional degree;

means for manually selecting priority, said priority selecting means having at least respective microphone and radio priority positions, said priority selecting means coupled to the microphone and radio signal detector means and to the microphone and radio mute means whereby at least one of said microphone or radio signals may be selected and operatively connected to the radio or microphone mute means, respectively, thereby lowering the non-selected input signal by a predetermined fractional degree in response to a detected selected signal whereby fractionally muting the non-selected signal enhances the selected signal intelligibility without interrupting the continuity of the non-selected signal.

5. The apparatus for integrating disparate audio sources of claim 4 including other signal summation input means;

other signal mute means operatively coupled to the microphone and radio signal detector means for lowering the other input signal by a predetermined third non-zero fractional degree in response to detected radio or microphone signals whereby fractionally muting the other signal enhances microphone and radio signals intelligibility without appreciably interrupting the continuity of said other signals.

6. The apparatus for integrating disparate audio sources of claim 4 wherein the priority selecting means defines a first radio priority position wherein the radio signal detector means is operatively coupled to the microphone mute means and a second microphone priority position wherein the microphone signal detector means is operatively coupled to the radio mute means.

7. The apparatus for integrating disparate audio sources of claim 6 wherein the priority selecting means defines a third non-priority position wherein the microphone and radio signal detector means are not coupled to the microphone and radio mute means.

8. Aircraft audio intercom apparatus including unitary amplifier means having output means for connecting a plurality of remote headsets whereby the same amplifier output signal is available to each headset;

a plurality of input means for connecting microphone audio to each such means, said microphone audio defining a first signal level generally representative of ambient cabin aircraft noise and a second signal level generally representative of said ambient cabin aircraft nosie and voice audio of an aircraft occupant using said microphone;

microphone switch means operatively coupling selected microphone input means to the amplifier means;

microphone actuator means operatively connected to the switch means and to the input means, said actuator means including means for separately detecting an audio input signal at each of the microphone input means whereby the actuator and switch means automatically couple each input means having said second signal level audio to the amplifier means without regard to audio input signal levels on the remaining audio input means.

9. The aircraft intercom apparatus of claim 8 wherein said switch means is comprised of a plurality of electrically operated switches, one switch interposed between each of said plural audio input means and the amplifier means and wherein said means for separately detecting an audio input signal at each microphone input means includes an audio detector coupled to each of said plural audio input means and to the respective audio input switch.

10. The aircraft audio intercom apparatus of claim 9 including light indicator means operatively coupled to each audio detector thereby providing independent visual indications of voice audio on each microphone input means.

11. Aircraft audio intercom apparatus including unitary amplifier means, means for connecting the output of the amplifier means to a plurality of remote headsets whereby the same amplifier output signal is available to each headset;

a plurality of microphone input means;

a plurality of microphone switch means, each of the switch means operatively coupling a respective one of the microphone input means to the amplifier means;

a plurality of audio detector means, each of the detector means having a detector input operatively connected to one of the audio input means and a detector output representative of the presence of an audio signal on the corresponding input means, the detector output operatively connected to the respective audio switch means associated with said one audio input means whereby only microphone input means having audio signals thereon are coupled to the amplifier means;

aircraft radio audio input means operatively coupled to the amplifier means;

entertainment input means operatively coupled to the amplifier means;

means for partially muting a signal from the entertainment input means;

aircraft audio detector means having an input operatively connected to the aircraft audio input means and a detector output representative of the presence of an audio signal on the aircraft audio input means;

means operatively interconnecting the microphone detector means and the aircraft audio detector means with the entertainment mute means whereby the level of a signal at the amplifier means from the entertainment means may be partially muted in response to detected microphone input means signal or aircraft radio input means signals.

12. The aircraft intercom apparatus of claim 11 including microphone audio partial mute means and aircraft radio audio partial mute means;

priority means selectively interconnecting the microphone and aircraft detector means outputs with the microphone and aircraft partial mute means whereby a signal on one of said microphone and aircraft input means partially mutes a signal on the other of said input means.

13. The aircraft audio intercom apparatus of claim 11 wherein the amplifier means includes stereo left channel amplifier means and right channel amplifier means and wherein the entertainment input means includes stereo left channel input means operatively connected to the left channel amplifier means and right channel input means operatively connected to the right channel amplifier means and including microphone signal splitter means operatively associated with each microphone input means for connecting microphone audio signals to both of said left and right channel amplifier means;

aircraft radio signal splitter means operatively coupling the aircraft radio input means to both of said left and right channel amplifier means whereby the monophonic voice microphone audio signals and monophonic aircraft radio audio signals will be present at the output means of both of said amplifier means.

14. The aircraft audio intercom apparatus of claim 11 including aircraft radio audio switch means having a push-to-talk input whereby signals on the aircraft audio input are gated off in response to a push-to-transmit signal on said push-to-transmit input.

15. Aircraft audio intercom apparatus including unitary amplifier means having output means for connecting a plurality of remote headsets whereby the same amplifier output signal is available to each headset;

a plurality of microphone input means;

microphone switch means operatively coupling selected microphone input means to the amplifier means;

microphone actuator means operatively connected to the switch means and to the input means, said actuator means including means for separately detecting an audio input signal at each of the microphone input means whereby the actuator and switch means automatically couple each input means having an audio signal of predetermined amplitude thereon to the amplifier means without regard to audio input signal levels on the remaining audio input means;

wherein the amplifier means includes stereo left channel amplifier means and right channel amplifier means and including microphone signal splitter means operatively associated with each microphone input means for connecting microphone audio signals to both of said left and right channel amplifier means whereby the microphone voice audio signal will be present at the output means of both of said amplifier means.

16. Apparatus for integrating disparate audio sources for use in light aircraft or in other high noise environments comprising unitary driver means for generating a composite output signal representative of a driver input signal, audio output means associated with the output of the driver means for connection of a plurality of remote sound transducer means thereto whereby a substantially identical composite output signal will be present at all of the remote sound transducer means without regard to the source of audio comprising said composite output signal;

audio signal summation means operatively connected to the driver input having at least two audio inputs, said audio summation means functioning to combine the respective audio inputs to form a single composite signal;

each summation means audio input including an associated audio switch means, audio detector means, and audio input means for connection of an audio input signal thereto;

each audio switch means connected in series between the associated summation means audio input and the audio input means, and each audio switch means having a gate means whereby the switch means may be selectively controlled to a first closed-circuit condition whereby an audio input signal at the associated audio input means is substantially connected to the summation means audio input and a second open-circuit condition whereby an audio input signal at the associated audio input means is substantially removed from said audio input;

each audio signal detector means being operatively connected to the gate means of the associated switch means and to the associated audio input means, each detector means being unresponsive to audio input signals on other than the associated audio input means, whereby the detector means controls the associated switch means into the first closed-circuit condition whenever an audio input signal of predetermined amplitude is present at the associated audio input means without regard to the input signal condition on any other audio input means and into the second open-circuit condition following a predetermined interval in which an audio input signal at the associated audio input means has not exceeded the predetermined amplitude whereby only audio input signals having a predetermined amplitude contribute to the driver means output signal thereby improving the audio quality by eliminating noise present on unused audio signal inputs;

including a single dc level potentiometer operatively interconnected to each of the microphone audio detector means whereby the predetermined detection amplitude of all of the detectors may be simultaneously adjusted.