Audio systems, devices, and methods

1. An audio system comprising:

a signal processor configured to receive an input signal and generate a modified input signal by replacing a first portion of the input signal within a first range of frequencies with a modulated noise signal, wherein the modulated noise signal comprises a parametrically formulated noise signal modulated with a signal corresponding to the sum of a fixed value and a volume envelope of a second portion of the input signal and wherein the fixed value corresponds to an amount of hearing loss of a user, and wherein the parametrically formulated noise signal comprises a plurality of time-ordered periodic waves within the first range of frequencies.

2. The audio system of claim 1 , wherein replacing the first portion of the input signal comprises attenuating the first range of frequencies within the input signal and mixing the input signal having an attenuated first range of frequencies with the modulated noise signal.

3. The audio system of claim 2 , wherein the volume envelope of the second portion of the input signal comprises the volume envelope of the input signal within a second range of frequencies.

4. The audio system of claim 3 , wherein a portion of the second range of frequencies is higher than the first range of frequencies.

5. The audio system of claim 1 , wherein the audio system comprises a hearing aid.

6. The audio system of claim 1 , wherein replacing the first portion of the input signal comprises filtering out the first range of frequencies from the input signal and mixing the filtered input signal with the modulated noise signal.

7. The audio system of claim 6 , wherein the volume envelope of the second portion of the input signal comprises the volume envelope of the input signal within a second ranged of frequencies.

8. The audio system of claim 7 , wherein a portion of the second range of frequencies is higher than the first range of frequencies.