Reverberation

As ringing the free will vibration designates that after the end of the outer excitation in the transition to the rest position occurs. Longer ringing is a sign of poor damping .

Examples

• In music
  • while string instruments resonate for a long time, wind instruments deliver a rather dry (low-resonance) sound
  • Post-oscillation can be disturbing, e.g. B. the long swinging of the bass drum in Haydn or jazz concerts and is prevented by the flat hand of the harpist placed on the strings or the felt of the piano
  • Desired reverberation (typically when playing the harp or when pressing the right pedal on a piano) enables simultaneous sounding of strings struck / plucked one after the other
• Room acoustics , building acoustics
  • Reverberation can be desirable or annoying. It can be avoided by sound insulation and can be reinforced by heavy, smooth walls or by cavity resonators built into the walls. Reverberation can also be generated electronically or electromechanically, see effects device (music) or spring reverb .
  • Floors are not only built to be particularly rigid to insulate footfall sound - they should not vibrate
• Transducer
  • With loudspeakers and boxes , ringing is generally undesirable because it falsifies the reproduction. However, it occurs in particular with the bass reflex principle and poor speakers and is accepted, especially with low frequencies and certain musical styles
  • Ultrasonic transducers should be low in post-oscillation especially when they are used for measuring purposes (pulse distance measurement).
• technology
  • Structures such as bridges and high-rise buildings or towers should have short post-oscillation times so that they do not oscillate excessively in the event of a storm or rhythmic load (see also resonance catastrophe ). They are therefore built to be particularly rigid and / or provided with damping (see damper pendulum )
  • Acousto-optical modulators should have low resonance so that the optical signal can be switched quickly

characterization

In terms of amplitude, the post-oscillation usually has an exponential course like a damped oscillation. However, effects such as air friction can steepen the decay process depending on the amplitude. The reverberation is characterized by the reverberation time and (with reverberation) by the spectral distribution.

The reverberation is a decisive characteristic of many musical instruments and can also be influenced in many. Different instruments of the same type often differ in terms of different post-oscillation spectra and times.