Acoustic membrane

A vibrating diaphragm or Oszillationsmembrane (membrane, from Middle High German Membrane " ( piece ) Parchment ", from Latin membrana " pellicle " or membrum " limb " ), is a thin skin or film, create or modify the vibrations should.

Each membrane has several resonances ( partials ), but which are often heavily damped. In their surroundings amplitudes can reach very high values. The diaphragm may be clamped in a fixed frame as a drum, but its edge can swing freely like a loudspeaker. Both versions differ very significantly regarding possible modes and frequencies.

It can be used for generation, amplification, recording, and measuring the vibration damping. The inspiration for membrane oscillations requires that a continuously acting external force is present, which is given by the tensile stress by a mounting edge. The vibrational excitation can be communicated in different ways, such as incidence of airborne sound, such as eardrum, by striking with a mallet, such as membranophones, or by electrical means, such as by excitation of a speaker cone.

Such vibrating membranes play in acoustics in many areas an extremely important role, so mainly in the electro- acoustic transducers, where they are used for converting mechanical sound energy into electrical energy, such as the microphone, or vice versa for the conversion of electrical energy into sound energy such as the speaker or the headphones, the listening process, and of some musical instruments, such as the membranophones. In the chest piece of the stethoscope diaphragm is also included.

Technical vibrating diaphragms are used for example in pressure gauges, diaphragm pumps and instruments use. An example of a biological membrane is vibrating the tympanic membrane.

• Soft Matter
• Acoustics