74:
1068:
842:
Amplitude envelope refers to the changes in the amplitude of a sound over time, and is an influential property as it affects perception of timbre. A flat tone has a steady state amplitude that remains constant during time, which is represented by a scalar. Other sounds can have percussive amplitude
855:
With waveforms containing many overtones, complex transient timbres can be achieved by assigning each overtone to its own distinct transient amplitude envelope. Unfortunately, this has the effect of modulating the loudness of the sound as well. It makes more sense to separate loudness and harmonic
846:
Percussive amplitude envelopes are characteristic of various impact sounds: two wine glasses clinking together, hitting a drum, slamming a door, etc. where the amplitude is transient and must be represented as either a continuous function or a discrete vector. Percussive amplitude envelopes model
315:
is simple and unambiguous only for symmetric periodic waves, like a sine wave, a square wave, or a triangle wave. For an asymmetric wave (periodic pulses in one direction, for example), the peak amplitude becomes ambiguous. This is because the value is different depending on whether the maximum
439:
are calibrated for RMS amplitude, but respond to the average value of a rectified waveform. Many digital voltmeters and all moving coil meters are in this category. The RMS calibration is only correct for a sine wave input since the ratio between peak, average and RMS values is dependent on
756:
The units of the amplitude depend on the type of wave, but are always in the same units as the oscillating variable. A more general representation of the wave equation is more complex, but the role of amplitude remains analogous to this simple case.
1072:
316:
positive signal is measured relative to the mean, the maximum negative signal is measured relative to the mean, or the maximum positive signal is measured relative to the maximum negative signal (the
197:
866:
In Sound
Recognition, max amplitude normalization can be used to help align the key harmonic features of 2 alike sounds, allowing similar timbres to be recognized independent of loudness.
407:
For complicated waveforms, especially non-repeating signals like noise, the RMS amplitude is usually used because it is both unambiguous and has physical significance. For example, the
359:(lowest amplitude value, which can be negative). With appropriate circuitry, peak-to-peak amplitudes of electric oscillations can be measured by meters or by viewing the waveform on an
151:
428:, the universal practice is to specify RMS values of a sinusoidal waveform. One property of root mean square voltages and currents is that they produce the same heating effect as a
114:
606:
435:
The peak-to-peak value is used, for example, when choosing rectifiers for power supplies, or when estimating the maximum voltage that insulation must withstand. Some common
444:. If the wave shape being measured is greatly different from a sine wave, the relationship between RMS and average value changes. True RMS-responding meters were used in
677:
863:
envelopes, where at each time frame all the harmonic amplitudes will add to 100% (or 1). This way, the main loudness-controlling envelope can be cleanly controlled.
1204:
745:
725:
703:
655:
629:
363:. Peak-to-peak is a straightforward measurement on an oscilloscope, the peaks of the waveform being easily identified and measured against the
956:
324:). In electrical engineering, the usual solution to this ambiguity is to measure the amplitude from a defined reference potential (such as
1027:
418:
or by an electrical signal is proportional to the square of the RMS amplitude (and not, in general, to the square of the peak amplitude).
1083:
1077:
1010:
775:
The amplitude of sound waves and audio signals (which relates to the volume) conventionally refers to the amplitude of the
495:
Pulse amplitude is measured with respect to a specified reference and therefore should be modified by qualifiers, such as
159:
1224:
1035:
453:
914:
367:. This remains a common way of specifying amplitude, but sometimes other measures of amplitude are more appropriate.
20:
826:
of the wave. However, radio signals may be carried by electromagnetic radiation; the intensity of the radiation (
815:
473:
276:
Semi-amplitude means half of the peak-to-peak amplitude. The majority of scientific literature employs the term
245:
988:
448:
measurements, where instruments measured the heating effect in a resistor to measure a current. The advent of
122:
328:
or 0 V). Strictly speaking, this is no longer amplitude since there is the possibility that a constant (
88:
1234:
919:
769:
469:
50:
543:
385:
54:
34:
808:
780:
396:
over time of the square of the vertical distance of the graph from the rest state; i.e. the RMS of the
53:
compared with a reference value. There are various definitions of amplitude (see below), which are all
908:
831:
827:
807:
and is one of the most salient qualities of a sound, although in general sounds it can be recognized
415:
325:
300:
38:
834:) is oscillated and then the individual oscillations are varied (modulated) to produce the signal.
422:
1128:"On the generalization of tones: A detailed exploration of non-speech auditory perception stimuli"
1190:
249:
1198:
993:
952:
875:
680:
58:
31:
662:
886:
761:
481:
381:
376:
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268:), the peak amplitude is the maximum absolute value of the difference from that reference.
1149:
1039:
1014:
804:
489:
485:
445:
411:
292:
859:
To do so, harmonic amplitude envelopes are frame-by-frame normalized to become amplitude
1229:
847:
many common sounds that have a transient loudness attack, decay, sustain, and release.
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449:
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261:
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944:
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401:
364:
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329:
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envelopes featuring an abrupt onset followed by an immediate exponential decay.
784:
747:
are arbitrary constants representing time and displacement offsets respectively.
397:
389:
222:
202:
1186:
896:
260:, peak amplitude is often used. If the reference is zero, this is the maximum
253:
46:
1032:
891:
811:. The square of the amplitude is proportional to the intensity of the wave.
788:
515:
436:
296:
288:
257:
218:
78:
42:
73:
19:
This article is about amplitude in classical physics. For other uses, see
800:
796:
523:
441:
1167:
792:
477:
819:
256:
is a signal that swings above and below a reference value but is not
776:
765:
72:
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quality to be parameters controlled independently of each other.
880:
393:
295:
semi-amplitudes of nearby stars is important in the search for
355:) is the change between peak (highest amplitude value) and
57:
of the magnitude of the differences between the variable's
65:
of a periodic function is sometimes called the amplitude.
456:
the waveform has made true RMS measurement commonplace.
287:
It is the most widely used measure of orbital wobble in
163:
126:
92:
733:
713:
691:
665:
643:
617:
546:
162:
125:
91:
1193:
from the original on 2021-11-08 – via YouTube.
994:
Universe of Light: What is the
Amplitude of a Wave?
192:{\displaystyle \scriptstyle {\hat {u}}/{\sqrt {2}}}
739:
719:
697:
671:
649:
623:
600:
191:
145:
108:
514:Pulse amplitude also applies to the amplitude of
452:-controlled meters capable of calculating RMS by
264:of the signal; if the reference is a mean value (
49:). The amplitude of a non-periodic signal is its
779:in the wave, but sometimes the amplitude of the
1150:"Additive Sound Synthesizer Project with CODE!"
1126:Schutz, Michael; Gillard, Jessica (June 2020).
978:Paragraph 18.2.12. 2007. Retrieved 2008-08-22.
791:of the amplitude squared is usually quoted in
8:
783:(movements of the air or the diaphragm of a
1203:: CS1 maint: numeric names: authors list (
1168:"Sound Sampling, Analysis, and Recognition"
1187:"I wrote a Sound Recognition Application"
732:
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690:
664:
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545:
181:
176:
165:
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131:
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94:
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90:
146:{\displaystyle \scriptstyle 2{\hat {u}}}
16:Measure of change in a periodic variable
936:
109:{\displaystyle \scriptstyle {\hat {u}}}
37:is a measure of its change in a single
1196:
1026:Department of Communicative Disorders
795:, so a null amplitude corresponds to −
384:(RMS) amplitude is used especially in
830:) or the frequency of the radiation (
601:{\displaystyle x=A\sin(\omega )+b\ ,}
7:
974:Physics – Celestial Mechanics
632:
217:For symmetric periodic waves, like
949:Theory of Functions Parts I and II
822:corresponds to the changes in the
332:) is included in the measurement.
14:
1056:, pp. 141–142, McGraw-Hill, 1971.
951:. Dover Publications. p. 3.
213:Peak amplitude and semi-amplitude
1071: This article incorporates
1066:
1017:, pp. 2–3. Retrieved 2008-08-22.
1084:General Services Administration
1028:University of Wisconsin–Madison
320:) and then divided by two (the
1054:Electrical Engineering Science
947:; Bagemihl, Frederick (1996).
583:
580:
568:
562:
414:transmitted by an acoustic or
170:
136:
99:
1:
920:Atmospheric thermal amplitude
291:and the measurement of small
803:is related to amplitude and
657:is the oscillating variable,
388:: the RMS is defined as the
156:Root mean square amplitude (
1185:rblack37 (2 January 2018).
997:1996. Retrieved 2008-08-22.
1253:
809:independently of amplitude
374:
371:Root mean square amplitude
21:Amplitude (disambiguation)
18:
816:electromagnetic radiation
764:, or in a medium such as
246:audio system measurements
989:University of California
284:to mean semi-amplitude.
119:Peak-to-peak amplitude (
1043:. Retrieved 2008-08-22.
851:Amplitude normalization
672:{\displaystyle \omega }
476:parameter, such as the
464:In telecommunications,
432:in a given resistance.
377:RMS of common waveforms
311:In general, the use of
1079:Federal Standard 1037C
1073:public domain material
883:and their properties:
741:
721:
699:
673:
651:
625:
602:
386:electrical engineering
341:Peak-to-peak amplitude
336:Peak-to-peak amplitude
318:peak-to-peak amplitude
209:
193:
147:
110:
61:. In older texts, the
818:, the amplitude of a
768:, the amplitude is a
742:
722:
700:
674:
652:
631:is the amplitude (or
626:
603:
530:Formal representation
375:Further information:
252:and others where the
194:
148:
111:
76:
1103:"amplitude envelope"
909:Amplitude modulation
832:frequency modulation
828:amplitude modulation
787:) is described. The
731:
711:
689:
663:
641:
615:
544:
416:electromagnetic wave
301:Doppler spectroscopy
160:
123:
89:
1225:Physical quantities
1006:Goldvais, Uriel A.
838:Amplitude envelopes
423:alternating current
1132:Scientific Reports
1038:2013-09-11 at the
1013:2021-03-03 at the
737:
717:
695:
669:
647:
621:
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250:telecommunications
210:
205:(not an amplitude)
189:
188:
143:
142:
106:
105:
958:978-0-486-69219-7
915:thermal amplitude
876:Complex amplitude
740:{\displaystyle b}
720:{\displaystyle K}
698:{\displaystyle t}
681:angular frequency
650:{\displaystyle x}
624:{\displaystyle A}
594:
186:
173:
139:
102:
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1086:. Archived from
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509:root-mean-square
382:Root mean square
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85:Peak amplitude (
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1101:
1100:
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1051:
1047:
1040:Wayback Machine
1025:
1021:
1015:Wayback Machine
1005:
1001:
987:Regents of the
986:
982:
970:
966:
959:
943:
942:
938:
933:
872:
853:
840:
760:For waves on a
754:
729:
728:
709:
708:
687:
686:
661:
660:
639:
638:
613:
612:
542:
541:
534:In this simple
532:
486:field intensity
466:pulse amplitude
462:
460:Pulse amplitude
446:radio frequency
379:
373:
338:
309:
293:radial velocity
274:
242:
215:
208:
158:
157:
121:
120:
87:
86:
71:
24:
17:
12:
11:
5:
1250:
1249:
1246:
1238:
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1235:Wave mechanics
1232:
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1177:
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1141:
1118:
1094:
1090:on 2022-01-22.
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824:electric field
753:
750:
749:
748:
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684:
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633:peak amplitude
620:
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531:
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461:
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450:microprocessor
430:direct current
426:electric power
372:
369:
337:
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322:semi-amplitude
313:peak amplitude
308:
305:
282:peak amplitude
273:
272:Semi-amplitude
270:
262:absolute value
241:
240:Peak amplitude
238:
236:are the same.
234:semi amplitude
230:peak amplitude
227:triangle waves
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185:
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59:extreme values
47:spatial period
15:
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1074:
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1037:
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1033:RMS Amplitude
1029:
1023:
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1016:
1012:
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990:
984:
981:
977:
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971:Tatum, J. B.
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945:Knopp, Konrad
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734:
714:
707:
692:
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682:
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589:
586:
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574:
571:
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559:
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547:
540:
539:
538:
537:
536:wave equation
529:
527:
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521:
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501:instantaneous
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343:(abbreviated
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1172:www.pitt.edu
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1162:
1154:www.pitt.edu
1153:
1144:
1135:
1131:
1121:
1110:. Retrieved
1106:
1097:
1088:the original
1078:
1061:
1053:
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1031:
1022:
1002:
992:
983:
972:
967:
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939:
902:Crest factor
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860:
858:
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845:
841:
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781:displacement
777:air pressure
774:
770:displacement
759:
755:
533:
513:
508:
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494:
465:
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420:
408:
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402:DC component
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361:oscilloscope
352:
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330:DC component
321:
317:
312:
310:
286:
281:
277:
275:
266:DC component
243:
233:
229:
223:square waves
216:
27:
25:
925:Wave height
526:envelopes.
522:-modulated
398:AC waveform
390:square root
203:Wave period
69:Definitions
1219:Categories
1112:2023-10-30
1008:Exoplanets
897:Wavelength
861:proportion
799: dB.
437:voltmeters
297:exoplanets
258:sinusoidal
219:sine waves
79:sinusoidal
1107:MAPLE Lab
892:Frequency
805:intensity
789:logarithm
667:ω
575:−
566:ω
560:
516:frequency
470:magnitude
400:(with no
365:graticule
307:Ambiguity
289:astronomy
278:amplitude
254:measurand
171:^
137:^
100:^
55:functions
51:magnitude
41:(such as
28:amplitude
1199:cite web
1191:Archived
1036:Archived
1011:Archived
887:Envelope
870:See also
801:Loudness
705:is time,
524:waveform
454:sampling
442:waveform
35:variable
32:periodic
785:speaker
497:average
492:level.
484:level,
482:current
480:level,
478:voltage
468:is the
409:average
392:of the
1052:Ward,
955:
820:photon
762:string
593:
518:- and
357:trough
326:ground
81:curve
39:period
1230:Sound
1075:from
931:Notes
913:Body
881:Waves
766:water
752:Units
520:phase
507:, or
490:power
488:, or
474:pulse
472:of a
412:power
299:(see
63:phase
30:of a
1205:link
953:ISBN
814:For
727:and
505:peak
421:For
394:mean
353:PtoP
232:and
43:time
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679:is
557:sin
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351:or
349:PtP
347:or
345:p–p
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280:or
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225:or
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
