Abstract: A method for planning, constructing and/or maintaining a pipeline system having a plurality of line sections, includes storing material data, for example, in a first memory, and storing data relating to pipe components in a second memory. A material may be selected, using the two memories, from line parameters assigned to a line section, a maximum permissible transversal stress is determined, an external diameter is selected and a minimum wall thickness is determined. The next largest wall thickness of an available pipe component is specified. A uniquely defined pipe class is generated for the line section from the line parameters, the material and the next largest wall thickness. The pipe class which is preferably generated by an EDP system in an automated manner permits a selective and error-free selection of a pipe component which is to be installed in the line section. A data processing system for carrying out the method is also provided.

Abstract: A hearing aid that has an analog part with a Class D final amplifier stage for audio signal processing, a digital part with an interface, a memory stage as well as supply stage for generating the voltage and control signals. The hearing aid has a utilized integrated circuit which also includes a pre-amplifier stage with two inputs respectively connected to a microphone and a telephone coil, the signals from the two inputs being selectively pre-amplified individually or in common, with selectable or programmable gains. This gives the hearing aid a small structural size, a comprehensive functionality, versatile adaptability and especially low energy consumption.

Abstract: A hearing aid has a microphone, an amplifier and a receiver and at least one frequency-defining element in series with a switch connected to the amplifier. For telephone listening, the switch is closed and the frequency-defining element lowers the high frequencies in the incoming signal from the telephone receiver so that a comfortable tone results for the hearing-impaired person using the telephone. The frequency-defining element may be a part of a frequency-dependent voltage divider, a part of a frequency-dependent negative feedback circuit, or a component in a resonant circuit.

Abstract: An exemplary embodiment comprises an acoustic signal pickup, amplification and reproduction sections wherein the latter contains a plurality of sound sources which influence a shared sound transmission arrangement collecting the sound, influencing it upon formation of a specific transfer characteristic. Given such hearing aids, the originally set frequency characteristic should also be maintained given the maximally attainable output level. To this end, the disclosure provides two identical sound sources, proceeding from which the generated sound is supplied to the ear with specific adaptation to a particular individual hearing loss. For example, the desired transfer characteristic is achieved by establishing selected differential transmission properties for the respective acoustic channels leading from the respective sound sources to the shared passage leading to the ear. An inventively improved hearing aid is particularly suitable for employment as a hearing prothesis for hearing-impaired persons.