| 摘要 |
This invention describes a practical application of noise reduction in heati ng aids. Although listening in noisy conditions is difficult for persons with normal hearing, heating impaired individuals are at a considerable farther disadvantage. Under light noise conditions, conventional hearing aids amplify the input signal sufficiently to overcome the hearing loss, For a typical sloping hearing loss where there is a loss in high frequency hearing sensitivity, the amount of boost (or gai n) rises with frequency. Most frequently, the loss in sensitivity is only for low-level signals; high level signals are affecaive minimally or not at alt. A compression haring aid is able to compensate by automatically lowering the gain as tire input signal level trees. This compression action is usually compromised under noisy conditions. In general, hearing aids are of lesser benefit under nosiy conditions since both noise and speech are boosted togedter when what is really required is a reduction of the noise relative to the speech. A noise reducti on algorithm with the dual purpose of
|
