LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS

Introduced: September 1968

Last revised: January 1995

Classification Context

Section:: ELECTRICITY
Class:: ELECTRIC COMMUNICATION TECHNIQUE
Subclass:: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS

Description

H04R encompasses devices that convert between acoustic signals and electrical signals for sound reception, reproduction, or amplification. This subclass covers loudspeakers and related output transducers, microphones and input transducers, gramophone pick-ups, and acoustic-electromechanical transducers of similar type. It also includes electric hearing aids designed to amplify sound for hearing-impaired individuals and public address systems that project audio to large audiences. Excluded are purely mechanical sound reproduction devices and non-acoustic applications of electromagnetic transducers.

Scope Notes

Glossary: Acoustic Sound sounds cover the technical field dealing with ultrasonic, sonic or infrasonic waves Deaf aid hearing aid Loudspeaker Loudspeakers transducer generally mounted in a casing for producing sound Microphone microphones transducer generally mounted in a casing for collecting sound Stereophonic system stereophonic systems two- or more channel system, e.g. quadraphonic, ambisonic or similar system Transducer Transducers a device that converts an electrical signal to an acoustic signal with a frequency which is determined by the frequency of the electrical signal applied to the transducer, or vice versa

Related Keywords

pick-ups for GRAMOPHONE(S)LOUDSPEAKERSMAGNETS used in electro-mechanical transducersMICROPHONESMOUTHPIECES for electro-mechanical transducersPICK-UP(S) for gramophonestransducers for telephonic RECEIVERStransducers for REPRODUCTION of soundcone speakersmicrophones for STETHOSCOPESelectromechanical transducers for TELECOMMUNICATIONtelephone receiverstransducers for TELEPHONE(S)transducers for telephonic TRANSMITTERS

16 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

H04R 1/00 Details of transducers
H04R 11/00 Transducers of moving-armature or moving-core type
H04R 13/00 Transducers having an acoustic diaphragm of magnetisable material directly co-acting with electromagnet
H04R 15/00 Magnetostrictive transducers
H04R 17/00 Piezoelectric transducers; Electrostrictive transducers
H04R 19/00 Electrostatic transducers
H04R 21/00 Variable-resistance transducers
H04R 23/00 Transducers other than those covered by groups
H04R 25/00 Electric hearing aids
H04R 27/00 Public address systems
H04R 29/00 Monitoring arrangements; Testing arrangements
H04R 3/00 Circuits for transducers
H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
H04R 5/00 Stereophonic arrangements
H04R 7/00 Diaphragms for electromechanical transducers; Cones
H04R 9/00 Transducers of moving-coil, moving-strip, or moving-wire type