Method and apparatus to facilitate provision and use of an energy value to determine a spectral envelope shape for out-of-signal bandwidth content

1. A method for rendering audible content in a bandwidth extension system comprising:

providing, by a speech encoder in the bandwidth extension system, a digital audio signal having a corresponding signal bandwidth;

generating, by a speech decoder in the bandwidth extension system, an energy value that represents at least an estimate of entire energy contained in an out-of-signal bandwidth content as corresponds to the digital audio signal;

generating, by the speech decoder, a starting magnitude value for the out-of-signal bandwidth spectrum;

normalizing, by the speech decoder, the energy value using the starting magnitude value;

using, by the speech decoder:

the normalized energy value to determine a spectral envelope shape; and

the starting magnitude value to determine a corresponding suitable energy for the spectral envelope shape;

for the out-of-signal bandwidth content as corresponds to the digital audio signal.

2. The method of claim 1 wherein providing a digital audio signal comprises providing, by the speech encoder, synthesized vocal content.

3. The method of claim 1 wherein using the energy value comprises, at least in part, using the normalized energy value to access a look-up table containing a plurality of corresponding candidate spectral envelope shapes.

4. The method of claim 1 wherein the out-of-signal bandwidth content comprises energy that is representative of signal content that is higher in frequency than the corresponding signal bandwidth of the digital audio signal.

5. The method of claim 1 wherein the out-of-signal bandwidth content comprises energy that is representative of signal content that is lower in frequency than the corresponding signal bandwidth of the digital audio signal.

6. The method of claim 1 further comprising:

combining, by the speech decoder, the digital audio signal with the out-of-signal bandwidth content to provide a bandwidth extended version of the digital audio signal to be audibly rendered to thereby improve corresponding audio quality of the digital audio signal as so rendered.

7. The method of claim 6 wherein the out-of-signal bandwidth content overlaps with, and comprises a portion of, content that is within the corresponding signal bandwidth.

8. The method of claim 7 wherein combining the digital audio signal with the out-of-signal bandwidth content further comprises combining the portion of content that is within the corresponding signal bandwidth with a corresponding in-band portion of the digital audio signal.

9. An apparatus comprising:

an input configured and arranged to receive a digital audio signal having a corresponding signal bandwidth;

a processor operably coupled to the input and being configured and arranged to:

generate an energy value that represents at least an estimate of entire energy contained in an out-of-signal bandwidth content as corresponds to the digital audio signal;

generate a starting magnitude value for the out-of-signal bandwidth spectrum;

normalize the energy value using the starting magnitude value;

use the normalized energy value to determine a spectral envelope shape and the starting magnitude value to determine

a corresponding suitable energy for the spectral envelope shape;

for the out-of-signal bandwidth content as corresponds to the digital audio signal.

10. The apparatus of claim 9 wherein the digital audio signal comprises synthesized vocal content.

11. The apparatus of claim 9 wherein the processor is further configured and arranged to use the normalized energy value and a set of energy-indexed shapes to determine a spectral envelope shape for out-of-signal bandwidth content as corresponds to the digital audio signal by, at least in part, using the normalized energy value to access a look-up table containing a plurality of corresponding candidate spectral envelope shapes.

12. The apparatus of claim 9 wherein the out-of-signal bandwidth content comprises energy that is representative of signal content that is higher in frequency than the corresponding signal bandwidth of the digital audio signal.

13. The apparatus of claim 9 wherein the out-of-signal bandwidth content comprises energy that is representative of signal content that is lower in frequency than the corresponding signal bandwidth of the digital audio signal.

14. The apparatus of claim 9 wherein the processor is further configured and arranged to:

combine the digital audio signal with the out-of-signal bandwidth content to provide a bandwidth extended version of the digital audio signal to be audibly rendered to thereby improve corresponding audio quality of digital audio signal as so rendered.

15. The apparatus of claim 14 wherein the out-of-signal bandwidth content overlaps with, and comprises a portion of, content that is within the corresponding signal bandwidth.

16. The apparatus of claim 15 wherein the processor is further configured and arranged to combine the digital audio signal with the out-of-signal bandwidth content further by combining the portion of content that is within the corresponding signal bandwidth with a corresponding in-band portion of the digital audio signal.

17. The apparatus of claim 9 wherein the apparatus comprises a two-way communications device.

18. The apparatus of claim 17 wherein the two-way communications device comprises a wireless two-way communications device.