Systems and methods for enhancing audio content
Systems and methods operate on multi-channel audio content having audio content spanning a plurality of frequency bands. The process can be configured to analyze audio content to identify one or more frequency bands of the plurality of frequency bands associated with a first channel having a signal level below a predetermined threshold; increase the gain of the identified frequency band(s) in the first channel; altering the gain of the identified frequency band(s) in the second channel relative to the first channel; phase shifting the first channel relative to the second channel to create modified first and second channels; creating a master channel signal comprising the modified first and second channels; separating the master channel signal into a plurality of frequency bands; and processing each frequency band in the master channel with an audio compressor to adjust attack and release times of master channel signals in multiple frequency bands.
1. A method for modifying an audio file, comprising: receiving an electronic file containing multi-channel audio content in digital form, the multi-channel audio content comprising a first channel having first-channel audio content spanning a plurality of frequency bands and a second channel having second-channel audio content spanning a plurality of frequency bands; analyzing the first-channel audio content using a spectrum analyzer to characterize signal levels of the plurality of frequency bands associated with the first channel; identifying a first frequency band of the plurality of frequency bands associated with the first channel having a signal level below a predetermined threshold; increasing the gain of the first frequency band in the first channel to a level within a predetermined range; identifying a second frequency band of the plurality of frequency bands associated with the first channel having a signal level below a predetermined threshold; increasing the gain of the second frequency band in the first channel to a level within a predetermined range; analyzing the second-channel audio content using the spectrum analyzer to view signal levels of the plurality of frequency bands associated with the second channel; identifying a first frequency band in the second channel corresponding to the first frequency band in the first channel; increasing the gain of the first frequency band in the second channel by an amount sufficient to bring a level of the first frequency band in the second channel to a level below the level of the first frequency band in the first channel; identifying a second frequency band in the second channel corresponding to the second frequency band in the first channel; increasing the gain of the second frequency band in the second channel to increase the signal to a level greater than the increased level of the second frequency band in the first channel; phase shifting the first channel relative to the second channel; creating a master channel signal comprising the first and second channels as modified by the applied gains and phase shifting; separating the master channel signal into a plurality of frequency bands; and processing each frequency band in the master channel with an audio compressor to adjust attack and release times of master channel signals in multiple frequency bands.
2. The method of claim 1 , wherein separating the master channel signal into a plurality of frequency bands comprises separating the master channel into a low frequency band, a middle frequency band and a high frequency band.
3. The method of claim 2 , wherein for the low frequency band, the audio compressor attack is set within range of 50 to 70 milliseconds and the audio compressor release is set within range of 30 to 55 milliseconds.
4. The method of claim 2 , wherein for the low frequency band, the level is set within a range between +2 to +7 dB.
5. The method of claim 4 , wherein for the low frequency band, the level is held in a dB range so that it cannot dip 12 dB below from the set range.
6. The method of claim 2 , wherein for the mid frequency band, the audio compressor attack is set within range of 40 to 65 milliseconds and the audio compressor release is set within range of 5 to 45 milliseconds.
7. The method of claim 2 , wherein for the mid frequency band, the level is set within a range between +1 to +3 dB.
8. The method of claim 7 , wherein for the mid frequency band, the level is held in a dB range so that it cannot dip 12 dB below from the +1 to +3 dB range.
9. The method of claim 2 , wherein for the high frequency band, the audio compressor attack is set within range of 10 to 30 milliseconds and the audio compressor release is set within range of 0 to 10 milliseconds.
10. The method of claim 2 , wherein for the high frequency band, the level is set within a range between +2 to +7 dB.
11. The method of claim 7 , wherein for the high frequency band, the level is held in a dB range so that it cannot dip 12 dB below from the +2 to +7 dB range.
12. The method of claim 2 , wherein the predetermined threshold is set as the average level of all frequency bands of the audio content in that channel, or as the average level of all frequency bands other than the frequency band being analyzed, or as the average level of the M frequency bands in that channel having the highest signal levels.
13. The method of claim 1 , wherein separating the master channel signal into a plurality of frequency bands comprises separating the master channel into a low frequency band, a low mid frequency band, a middle frequency band, a high mid frequency band, and a high frequency band.
14. The method of claim 13 , wherein for the low frequency band, a low mid frequency band, a middle frequency band, a high mid frequency band, and a high frequency band, the frequency bands and predetermined signal level ranges are defined as:
Frequency Band
Frequency Range
Signal Level Range
Low Frequency
21.0 Hz to 90.0 Hz
0 dB to plus 8 dB
Low mid Frequency
91.0 Hz to 313.0 Hz
0 dB to plus 4 dB
Mid Frequency
314.0 Hz to 1.03 kHz
0 dB to plus 4 dB
High mid Frequency
1.04 kHz to 3.87 kHz
0 dB to plus 8 dB
High Frequency
3.88 kHz to 20.00 kHz
0 dB to plus 8 dB
15. A method for modifying an audio file, comprising: receiving an electronic file containing multi-channel audio content in digital form, the multi-channel audio content comprising a first channel having first-channel audio content spanning a plurality of frequency bands and a second channel having second-channel audio content spanning a plurality of frequency bands; analyzing the first-channel audio content using a spectrum analyzer to identify a frequency band of the plurality of frequency bands associated with the first channel having a signal level below a predetermined threshold; increasing the gain of the first frequency band in the first channel to bring the signal level to at or above the predetermined threshold; increasing the gain of the first frequency band in the second channel by an amount sufficient to bring a level of the first frequency band in the second channel to a level below the level of the first frequency band in the first channel; and phase shifting the first channel relative to the second channel to create modified first and second channels.
16. The method of claim 15 , further comprising:
creating a master channel signal comprising the modified first and second channels;
separating the master channel signal into a plurality of frequency bands; and
processing each frequency band in the master channel with an audio compressor to adjust attack and release times of master channel signals in multiple frequency bands.
17. A computer program product comprising a non-transitory computer useable medium having computer program code embodied therein for enabling a computing device to transform digital audio content in multiple channels, the transformation comprising: receiving an electronic file containing multi-channel audio content in digital form, the multi-channel audio content comprising a first channel having first-channel audio content spanning a plurality of frequency bands and a second channel having second-channel audio content spanning a plurality of frequency bands; analyzing the first-channel audio content using a spectrum analyzer to identify a frequency band of the plurality of frequency bands associated with the first channel having a signal level below a predetermined threshold; increasing the gain of the first frequency band in the first channel to bring the signal level to at or above the predetermined threshold; increasing the gain of the first frequency band in the second channel by an amount sufficient to bring a level of the first frequency band in the second channel to a level below the level of the first frequency band in the first channel; phase shifting the first channel relative to the second channel to create modified first and second channels.
18. The computer program product of claim 17 , wherein the transformation further comprises:
creating a master channel signal comprising the modified first and second channels;
separating the master channel signal into a plurality of frequency bands; and
processing each frequency band in the master channel with an audio compressor to adjust attack and release times of master channel signals in multiple frequency bands.
19. The computer program product of claim 17 , wherein the transformation further comprises:
increasing the gain of a second frequency band in the first channel to bring the signal level to at or above the predetermined threshold; and
increasing the gain of the second frequency band in the second channel by an amount sufficient to bring a level of the first frequency band in the second channel to a level above the level of the first frequency band in the first channel.