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Add a reverberation effect to the audio input.

Artificial reverberation is a widely-used audio effect and produces a sense of envelopment in the listener. Used correctly, it can generate the illusion of the audio being played in a different environment. In pop productions, one will usually want to add reverberation to individual tracks (like the vocals) while in classical productions it is not uncommon to add reverb to the complete mix.


Parameter Type Description
preset optional string [medium_hall, large_hall, plate, cathedral, room, room1, room2] default: medium_hall Preset for pre-configured room settings.

Choose a preset as a starting point for the room (size) you need and apply your parameter changes after that.

reverb_time optional float [0.4986 .. 1000] Reverberation time in seconds.

Rooms with a high volume will have a long reverberation time and rooms with low volume will have a short reverberation time. The reverberation of real room varies between app. 0.5s and 10s. (default depends on preset)

pre_delay optional float [0 .. 0.3] Delay of the wet output signal in seconds.

Change the 'presence' of the wet signal without changing the reverberation time. If you want a clearly recognizable reverberation tail but at the same time a original signal that has presence and does not appear to be far away in the room, increase this time. You won't hear this effect unless you mix with the dry signal. (default depends on preset)

high_cut optional float [100 .. 18000] Reverberation low pass frequency in Hertz.

Adjust the sound quality of the reverberation (soft walls -> low value, and vice versa). Lower the default if the output hisses or has to much high frequency content. (default depends on preset)

wetness optional float [0 .. 1] default: 0.2 Mixture of wet (reverberated) and original (dry) signal as a factor.

Use low values for a dry output signal and high values for a wet output signal: wetness*reverb + (1-wetness)*input. Decreasing the value will make the reverberation less appearant.

  • parameter interdependencies: Note that by setting the preset, all other parameters will be adjusted to the preset's default if not set explicitely.
  • wetness: while setting the wetness has some influence on the perceived amount of reverberation, you should only use this parameter if dry and wet signal are not mixed by your app
The following table lists the default parameter values per preset. Please note that even similar presets may sound different as there are a number of internal parameters adjusted as well.

Preset reverb_time pre_delay high_cut
medium_hall 1.34 0.01 8000
large_hall 2.18 0.02 6000
plate 1.84 0.001 16000
cathedral 4.10 0.035 5000
room 0.50 0.001 8000
room1 0.50 0.001 5000
room2 0.50 0.001 6000



The response gives you a status code, the file_id and the corresponding download URL of the resulting file (audio for process tasks and xml for analyze tasks). For processing reports, use the file/status request with the parameterformat=xml(p)/json(p).

Name Description
status The status code of the task.
file_id The unique identifier of the file.
href The direct download link to the file including the file_id.


The response will be the resulting audio file. If you request the file_id with format=xml(p)/json(p), you will receive additional info on the task, its parametrization, and the output file.

Name Description
warning If there is anything you should know about, we will tell you here.
output_info Information on the level of the output file: peak_level is the overall maximum level of the output file in dBFS - if peak level is higher than 0, clipped is set to true and you should consider actions to avoid the overload.
parameters Contains the values of all task parameters for this process.

One-click example

Add 'medium hall' reverberation to this saxophone recording with a simple click on this button:
Process Learn more The button is just a link with a specially constructed URL:
By requesting this URL, the input file will be imported into the system, processed by sonicAPI and the output file will be downloaded by your browser. The Live-Demo helps you to explore the available parameters and to generate some example code.

About the technology

The reverb task uses the z.reverb engine by zplane.development for high quality reverb generation.