Flutter Echo Modeling

Gloria Dal Santo*, Karolina Prawda, Vesa Välimäki

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

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Flutter echo is a well-known acoustic phenomenon that occurs when sound waves bounce between two parallel reflective surfaces, creating a repetitive sound. In this work, we introduce a method to recreate flutter echo as an audio effect. The proposed algorithm is based on a feedback structure utilizing velvet noise that aims to synthesize the fluttery components of a reference room impulse response presenting flutter echo. Among these, the repetition time defines the length of the delay line in a feedback filter. The specific spectral properties of the flutter are obtained with a bandpass attenuation filter and a ripple filter, which enhances the harmonic behavior of the sound. Additional temporal shaping of a velvet-noise filter, which processes the output of the feedback loop, is performed based on the properties of the reference flutter. The comparison between synthetic and measured flutter echo impulse responses shows good agreement in terms of both the repetition time and reverberation time values.
Original languageEnglish
Title of host publicationProceedings of the 25th International Conference on Digital Audio Effects (DAFx20in22)
Place of PublicationVienna, Austria
PublisherUniversität für Musik und darstellende Kunst Wien
Number of pages7
ISBN (Print)978-3-200-08599-2
Publication statusPublished - 6 Sept 2022
MoE publication typeA4 Conference publication
EventInternational Conference on Digital Audio Effects - University of Music and Performing Arts Vienna, Vienna, Austria
Duration: 7 Sept 20229 Sept 2022
Conference number: 25

Publication series

NameProceedings of the International Conference on Digital Audio Effects
ISSN (Print)2413-6700
ISSN (Electronic)2413-6689


ConferenceInternational Conference on Digital Audio Effects
Abbreviated titleDAFx
Internet address


  • audio signal processing
  • digital filter
  • artificial reverberation
  • reverb algorithm
  • flutter echo


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