1. A method for automatically controlling the volume of an audio signal, comprising:
calculating an average power associated with a segment of an input audio signal;
determining whether the average power is greater than an estimated signal level associated with one or more previously-processed segments of the input audio signal;
responsive to determining that the average power is not greater than the estimated signal level, calculating an updated estimated signal level by subtracting from the average power an attenuated difference between the estimated signal level and the average power;
responsive to determining that the average power is greater than the estimated signal level, setting the updated estimated signal level equal to the average power; and
determining a gain to be applied to the segment of the input audio signal based on the updated estimated signal level and a target signal level for an output audio signal.
2. The method of claim 1, wherein calculating an average power associated with a segment of the input audio signal comprises:
calculating an average power associated with a single frame of the input audio signal.
3. The method of claim 2, wherein calculating an average power associated with a single frame of the input audio signal comprises:
calculating an average power associated only with subframes within the single frame of the input audio signal that are determined to be active.
4. The method of claim 3, further comprising:
determining which subframes within the single frame of the input audio signal are active by comparing a signal energy associated with each subframe to a power threshold.
5. The method of claim 4, further comprising:
adaptively adjusting the power threshold responsive to a change in the level of the input audio signal.
6. The method of claim 1, wherein calculating an average power associated with a segment of the audio signal comprises:
calculating an average power associated with a plurality of frames of the input audio signal.
7. The method of claim 6, wherein calculating an average power associated with a plurality of frames of the input audio signal comprises:
calculating an average power associated only with samples that are determined to be active within the plurality of frames of the input audio signal.
8. The method of claim 1, further comprising:
determining if the average power exceeds a power threshold;
responsive to determining that the average power does not exceed the power threshold, determining the gain to be applied to the segment of the input audio signal based on the estimated signal level associated with the one or more previously-processed segments of the input audio signal and the target signal level for an output audio signal.
9. The method of claim 8, further comprising:
adaptively adjusting the power threshold responsive to a change in the level of the input audio signal.
10. The method of claim 1, further comprising:
generating a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain; and
applying the series of gain values to the segment of the input audio signal.
11. The method of claim 10, wherein generating a series of gain values comprises:
generating a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a first time period responsive to a determination that the average power is less than or equal to the estimated signal level; and
generating a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a second time period responsive to a determination that the average power is greater than the estimated signal level;
wherein the first time period is longer than the second time period.
12. A system for automatically controlling the volume of an audio signal, comprising:
an average segment power calculator configured to calculate an average power associated with a segment of an input audio signal;
a signal level estimator configured to determine whether the average power is greater than an estimated signal level associated with one or more previously-processed segments of the input audio signal, to calculate an updated estimated signal level by subtracting from the average power an attenuated difference between the estimated signal level and the average power responsive to a determination that the average power is not greater than the estimated signal level, and to set the updated estimated signal level equal to the average power responsive to a determination that the average power is greater than the estimated signal level; and
a gain determiner configured to determine a gain to be applied to the segment of the input audio signal based on the updated estimated signal level and a target signal level for an output audio signal.
13. The system of claim 12, wherein the average segment power calculator is configured to calculate an average power associated with a single frame of the input audio signal.
14. The system of claim 13, wherein the average segment power calculator is configured to calculate an average power associated only with subframes within the single frame of the input audio signal that are determined to be active.
15. The system of claim 14, wherein the average segment power calculator is further configured to determine which subframes within the single frame of the input audio signal are active by comparing a signal energy associated with each subframe to a power threshold.
16. The system of claim 15, further comprising:
a power threshold calculator configured to adaptively adjust the power threshold responsive to a change in the level of the input audio signal.
17. The system of claim 12, wherein the average segment power calculator is configured to calculate an average power associated with a plurality of frames of the input audio signal.
18. The system of claim 17, wherein the average segment power calculator is configured to calculate an average power associated only with samples that are determined to be active within the plurality of frames of the input audio signal.
19. The system of claim 12, wherein the signal level estimator is further configured to determine if the average power exceeds a power threshold and to determine the gain to be applied to the segment of the input audio signal based on the estimated signal level associated with the one or more previously-processed segments of the input audio signal and the target signal level for an output audio signal responsive to determining that the average power does not exceed the power threshold.
20. The system of claim 19, further comprising:
a power threshold calculator configured to adaptively adjust the power threshold responsive to a change in the level of the input audio signal.
21. The system of claim 12, further comprising:
a gain ramp generator configured to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain; and
a gain ramp applier configured to apply the series of gain values to the segment of the input audio signal.
22. The system of claim 21, wherein the gain ramp generator is configured to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a first time period responsive to a determination that the average power is less than or equal to the estimated signal level and to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a second time period responsive to a determination that the average power is greater than the estimated signal level;
wherein the first time period is longer than the second time period.
23. A computer program product comprising a computer-readable medium having computer program logic recorded thereon for enabling a processor to automatically control the volume of an audio signal, wherein the computer program logic comprises:
first means for enabling the processor to calculate an average power associated with a segment of an input audio signal;
second means for enabling the processor to determine whether the average power is greater than an estimated signal level associated with one or more previously-processed segments of the input audio signal;
third means for enabling the processor to calculate an updated estimated signal level by subtracting from the average power an attenuated difference between the estimated signal level and the average power responsive to a determination that the average power is not greater than the estimated signal level;
fourth means for enabling the processor to set the updated estimated signal level equal to the average power responsive to a determination that the average power is greater than the estimated signal level; and
fifth means for enabling the processor to determine a gain to be applied to the segment of the input audio signal based on the updated estimated signal level and a target signal level for an output audio signal.
24. The computer program product of claim 23, wherein the first means comprises means for enabling the processor to calculate an average power associated with a single frame of the input audio signal.
25. The computer program product of claim 24, wherein the first means comprises means for enabling the processor to calculate an average power associated only with subframes within the single frame of the input audio signal that are determined to be active.
26. The computer program product of claim 25, wherein the first means further comprises means for enabling the processor to determine which subframes within the single frame of the input audio signal are active by comparing a signal energy associated with each subframe to a power threshold.
27. The computer program product of claim 26, wherein the computer program logic further comprises:
means for enabling the processor to adaptively adjust the power threshold responsive to a change in the level of the input audio signal.
28. The computer program product of claim 23, wherein the first means comprises means for enabling the processor to calculate an average power associated with a plurality of frames of the input audio signal.
29. The computer program product of claim 28, wherein the first means comprises means for enabling the processor to calculate an average power associated only with samples that are determined to be active within the plurality of frames of the input audio signal.
30. The computer program product of claim 23, wherein the computer program logic further comprises:
means for enabling the processor to determine if the average power exceeds a power threshold; and
means for enabling the processor to determine the gain to be applied to the segment of the input audio signal based on the estimated signal level associated with the one or more previously-processed segments of the input audio signal and the target signal level for an output audio signal responsive to determining that the average power does not exceed the power threshold.
31. The computer program product of claim 30, wherein the computer program logic further comprises:
means for enabling the processor to adaptively adjust the power threshold responsive to a change in the level of the input audio signal.
32. The computer program product of claim 23, wherein the computer program logic further comprises:
means for enabling the processor to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain; and
means for enabling the processor to apply the series of gain values to the segment of the input audio signal.
33. The computer program product of claim 32, wherein the means for enabling the processor to generate a series of gain values comprises:
means for enabling the processor to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a first time period responsive to a determination that the average power is less than or equal to the estimated signal level; and
means for enabling the processor to generate a series of gain values that transition from the gain associated with the previously-processed segment of the input audio signal to the determined gain in a second time period responsive to a determination that the average power is greater than the estimated signal level;
wherein the first time period is longer than the second time period.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A heat shield configuration having a heat shield for shielding an object from heat andor noise having an internal surface facing toward the object and an external surface facing away from the object as well as an opening, which goes through the heat shield having internal surface and external surface, comprising:
a closure of said heat shield for at least partially closing the opening; and
an actuating device, which is implemented to open and close the closure as a function of a controlled variable relevant for the function of the object.
2. The heat shield configuration according to claim 1, wherein the controlled variable is selected from the group consisting of at least one of the following measured variables: temperature, pressure, velocity, acoustic signal, exhaust gas value, volume flow and operating volume.
3. The heat shield configuration according to claim 2, wherein said temperature is an ambient temperature or component temperature of the object.
4. The heat shield configuration according to claim 2, wherein said pressure is an internal pressure of the object.
5. The heat shield configuration according to claim 2, wherein said velocity is flow or travel velocity.
6. The heat shield configuration according to claim 2, wherein said acoustic signal is noise pressure.
7. The heat shield configuration according to claim 1, wherein the heat shield has at least one measuring device for measuring the measured variable.
8. The heat shield configuration according to claim 7, wherein the heat shield comprises means for analyzing the measurement results and control means for controlling the actuating device on the basis of the analysis of the measurement result.
9. The heat shield configuration according to claim 1, wherein the actuating device is one of a pneumatic, hydraulic, and electrical actuating device.
10. The heat shield configuration according to claim 9, wherein the actuating device is one of a servomotor and a vacuum unit.
11. The heat shield configuration according to claim 1, wherein the actuating device is implemented to open the closure if a specific limiting measured variable is exceeded and to close it in the event of a measured variable less than or equal to the limiting measured variable.
12. The heat shield configuration according to claim 11, wherein the actuating device is implemented to increasingly expose the opening with increasing distance from the limiting measured variable.
13. The heat shield configuration according to claim 1, wherein the closure is implemented to open toward the side of the external surface.
14. The heat shield configuration according to claim 1, wherein the actuating device is implemented to close the closure if a specific limiting measured variable is exceeded and to open it in the event of a measured variable less than or equal to the limiting measured variable.
15. The heat shield configuration according to claim 14, wherein the actuating device is implemented to increasingly open or close the opening with increasing difference from the limiting measured variable.
16. The heat shield configuration according to claim 1, wherein the closure is implemented as one of a slide, rotating slide, and flap.
17. The heat shield configuration according to claim 1, wherein at least one further closure, to be opened and closed as a function of a measured variable relevant for the function of the object, is provided for at least partially closing a further opening.
18. The heat shield configuration according to claim 17, wherein at least one further actuating device is provided, which is implemented to open and close the further closure.
19. The heat shield configuration according to claim 18, wherein the actuating device is implemented to open or close the further closure at a different limiting measured value than the first actuating device of the first closure.
20. The heat shield configuration according to claim 1, wherein the heat shield encloses the object to be shielded essentially on all sides.
21. The heat shield configuration according to claim 1, wherein the heat shield shields an object in the area of an internal combustion engine.
22. The heat shield configuration according to claim 21, the heat shield is for one of a catalytic converter, a diesel particulate filter, a turbocharger, and an exhaust system.