Patent ID: 6873709

Claim:
A method for amplifying sound signals in a multi-band sound processing system, said method comprising: receiving a signal level estimate for a channel signal corresponding to a particular frequency band of a sound signal; and determining a suitable gain amount for the channel signal based on the signal level estimate, wherein, when the signal level estimate has a high level, the suitable gain amount is constrained to preserve spectrum contrast across frequency bands, thereby preserving speech clarity and intelligibility, and wherein said determining comprises: producing an initial gain amount for the channel signal; comparing the signal level estimate for the channel signal to a first threshold amount and a second threshold amount; producing the suitable gain amount as the initial gain amount when said comparing determines that the signal level estimate is less than the first threshold amount; constraining the initial gain amount to a first extent and then producing the suitable gain amount as a first constrained initial gain amount when said comparing determines that the signal level estimate is greater than the first threshold amount and less than the second threshold amount; and constraining the initial gain amount to a second extent and then producing the suitable gain amount as a second constrained initial gain amount when said comparing determines that the signal level estimate is greater than the second threshold amount, the constraining to the second extent being more constraining than constraining to the first extent.