Abstract:
A circuitry is disclosed for a preferably programmable hearing aid with at least one microphone, at least one electronic signal processing circuit (3), at least one channel and one output transducer (7). The electronic signal processing circuit (3) has a regulation circuit for continuously determining or calculating one or several percent values of the input signal based on a continuous analysis and evaluation of the frequency and/or amplitude distribution of the input signal. These percent values are directly or indirectly used as control signals for regulating the amplification and/or the frequency response of the electronic signal processing circuit. At least one percentage generator (10) connected at the input side consists of an integrator (11), a first incrementing control stage (12) connected to the integrator (11) and a second counting down control stage (13) connected to the first control stage (12), as well as a comparing stage (14) with at least two inputs. The input of the circuit is directly or indirectly connected to the input of the comparing stage (14), whereas a second input of the comparing stage is connected to the output of the integrator (11) and is directly or indirectly connected to the signal processing circuit (3) through a combination and control logic (15) by at least one control line. Both outputs of the comparing stage (14) are connected to the control stage (12) or to the control stage (13).
Abstract:
A tunable wide band driver amplifier is disclosed. In an exemplary embodiment, an apparatus includes a first band selection circuit selectively connected between an output terminal of an amplifier and a circuit ground. The first band selection circuit configured to adjust an amplification band from a first frequency band to a second frequency band. The apparatus also includes a first harmonic reduction circuit selectively connected between the first band selection circuit and the circuit ground and configured to reduce 2nd harmonic frequencies associated with the first frequency band when the amplification band is set to the first frequency band.
Abstract:
The invention relates to the measurement and control of the perceived sound loudness and/or the perceived spectral balance of an audio signal. An audio signal is modified in response to calculations performed at least in part in the perceptual (psychoacoustic) loudness domain. The invention is useful, for example, in one or more of: loudness-compensating volume control, automatic gain control, dynamic range control (including, for example, limiters, compressors, expanders, etc.), dynamic equalization, and compensating for background noise interference in an audio playback environment. The invention includes not only methods but also corresponding computer programs and apparatus.