Digital Effects

In the wide field of audio reproducing devices, the use of large loudspeakers is not always possible according to size constraints (e.g. portable audio, laptop). This condition leads to the adoption of small loudspeakers characterized by a limited frequency extension in particular for the band below 100 Hz. Low frequencies are essential for a correct sound reproduction since a lack of these usually results in unpleasant feeling for many listeners. On the other hand, for such small systems, increasing the radiation level of the low frequencies (e.g. equalization) is not a solution since a signal distortion may appear. For this reason, many efforts have been made to enhance low frequency sound reproduction using algorithms based on the missing fundamental principle. This is a well known psychoacoustic phenomenon based on the perception of a pitch without the corresponding frequency actually being contained in the signal. Employing this effect it is possibile to create a virtual bass, overcoming the aforementioned problems ( loudspeakers size constraints).

The main topics are:

  • Virtual Bass
  • Artificial Reverberation

Related pubblications

  1. S Cecchi, E Moretti and F Piazza. A New Approach to Bass Enhancement Based on Prony's Method. In Proc. 15th # "International Conference on Digital Signal Processing". 2007, 535-538. BibTeX

    @inproceedings{cecchi-dsp-07,
	author = "Cecchi, S. and Moretti, E. and Piazza, F.",
	title = "{A New Approach to Bass Enhancement Based on Prony's Method}",
	booktitle = {{Proc. 15th } # "International Conference on Digital Signal Processing"},
	address = "Cardiff, UK",
	month = "Jul.",
	year = 2007,
	pages = "535-538"
}

  2. L Palestini, E Moretti, P Peretti, S Cecchi, L Romoli and F Piazza. Real Time Implementation of an ESPRIT-based Bass Enhancement Algorithm. In Proc. 125th # "Audio Engineering Society Convention" (). 2008, . BibTeX

    @inproceedings{palestini-aes-08,
	author = "Palestini, L. and Moretti, E. and Peretti, P. and Cecchi, S. and Romoli, L. and Piazza, F.",
	title = "{Real Time Implementation of an ESPRIT-based Bass Enhancement Algorithm}",
	booktitle = {{Proc. 125th } # "Audio Engineering Society Convention"},
	volume = "",
	number = "",
	address = "San Francisco, CA, USA",
	month = "Oct.",
	year = 2008,
	pages = ""
}

  3. A Primavera, S Cecchi, L Palestini, F Piazza and M Moschetti. A Hybrid Approach for Real-Time Room Acoustic Response Simulation. In Proc. 128th # "Audio Engineering Society Convention" . May 2010, . BibTeX

    @inproceedings{primavera-aes-10,
	title = "{A Hybrid Approach for Real-Time Room Acoustic Response Simulation}",
	author = "Primavera, A. and Cecchi, S. and Palestini, L. and Piazza, F. and Moschetti, M.",
	booktitle = {{Proc. 128th } # "Audio Engineering Society Convention"},
	volume = "",
	address = "London, UK",
	month = "May",
	year = 2010,
	pages = ""
}

  4. A Primavera, S Cecchi, P Peretti, L Romoli and F Piazza. An Advanced Implementation of a Digital Artificial Reverberator. In Proc. 130th # "Audio Engineering Society Convention" . May 2011, . BibTeX

    @inproceedings{primavera-aes-11,
	title = "{An Advanced Implementation of a Digital Artificial Reverberator}",
	author = "Primavera, A. and Cecchi, S. and Peretti, P. and Romoli, L. and Piazza, F.",
	booktitle = {{Proc. 130th } # "Audio Engineering Society Convention"},
	volume = "",
	address = "London,UK",
	month = "May",
	year = 2011,
	pages = ""
}

  5. A Primavera, S Cecchi, L Romoli, P Peretti and F Piazza. Approximation of real impulse response using IIR structures. In Proc. 19th # "European Signal Processing Conference" . 2011, . BibTeX

    @inproceedings{primavera-eusipco-11,
	title = "{Approximation of real impulse response using IIR structures}",
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and Peretti, P. and Piazza, F.",
	booktitle = {{Proc. 19th } # "European Signal Processing Conference"},
	volume = "",
	address = "Barcelona, Spain",
	month = "Aug.",
	year = 2011,
	pages = ""
}

  6. A Primavera, S Cecchi, L Romoli, P Peretti and F Piazza. A Low Latency Implementation of a Non Uniform Partitioned Overlap and Save Algorithm for Real Time Applications. In Proc. 131st # "Audio Engineering Society Convention" . 2011, . BibTeX

    @inproceedings{primavera-aes2-11,
	title = "{A Low Latency Implementation of a Non Uniform Partitioned Overlap and Save Algorithm for Real Time Applications}",
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and Peretti, P. and Piazza, F.",
	booktitle = {{Proc. 131st } # "Audio Engineering Society Convention"},
	volume = "",
	address = "New York, USA",
	month = "Oct.",
	year = 2011,
	pages = ""
}

  7. F Primavera Piazza and J Reiss. Audio Morphing for Percussive Hybrid Sound Generation. In Proc. 45th # "Audio Engineering Society Conference" . 2012, . BibTeX

    @inproceedings{primavera-aes3-12,
	title = "{Audio Morphing for Percussive Hybrid Sound Generation}",
	author = "Primavera, Piazza, F. and Reiss, J.",
	booktitle = {{Proc. 45th } # "Audio Engineering Society Conference"},
	volume = "",
	address = "Helsinki, Finland",
	month = "Mar.",
	year = 2012,
	pages = ""
}

  8. A Primavera, S Cecchi, L Romoli, M Gasparini and F Piazza. An Efficient DSP-Based Implementation of a Dynamic Convolution Approach Exploiting Principal Component Analysis. In Proc. 5th EDERC. 2012, 30-34. BibTeX

    @inproceedings{primavera-ederc-12,
	title = "{An Efficient DSP-Based Implementation of a Dynamic Convolution Approach Exploiting Principal Component Analysis}",
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and Gasparini, M. and Piazza, F.",
	booktitle = "{Proc. 5th EDERC}",
	address = "Amsterdam, The Netherlands",
	month = "Sep.",
	year = 2012,
	pages = "30-34"
}

  9. A Primavera, S Cecchi, L Romoli, F Piazza and M Moschetti. An Efficient DSP-Based Implementation of a Fast Convolution Approach with Non Uniform Partitioning. In Proc. 5th EDERC. 2012, 25-29. BibTeX

    @inproceedings{primavera-ederc2-12,
	title = "{An Efficient DSP-Based Implementation of a Fast Convolution Approach with Non Uniform Partitioning}",
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and and Piazza, F. and Moschetti, M.",
	booktitle = "{Proc. 5th EDERC}",
	address = "Amsterdam, The Netherlands",
	month = "Sep.",
	year = 2012,
	pages = "25-29"
}

  10. A Primavera, S Cecchi, L Romoli, M Gasparini and F Piazza. Approximation of Dynamic Convolution Exploiting Principal Component Analysis: Objective and Subjective Quality Evaluation. In Proc. 133rd # "Audio Engineering Society Convention" . 2012, . BibTeX

    @inproceedings{primavera-aes2-12,
	title = "{Approximation of Dynamic Convolution Exploiting Principal Component Analysis: Objective and Subjective Quality Evaluation}",
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and Gasparini, M. and Piazza, F.",
	booktitle = {{Proc. 133rd } # "Audio Engineering Society Convention"},
	volume = "",
	address = "San Francisco, CA, USA",
	month = "Oct.",
	year = 2012,
	pages = ""
}

  11. A Primavera, S Cecchi, L Romoli, P Peretti and F Piazza. A Low Latency Implementation of a Non Uniform Partitioned Convolution algorithm for Room acoustic simulation. Signal, Image and Video Processing, 2012. BibTeX

    @article{primavera-jsivp-12,
	author = "Primavera, A. and Cecchi, S. and Romoli, L. and Peretti, P. and Piazza, F.",
	title = "{A Low Latency Implementation of a Non Uniform Partitioned Convolution algorithm for Room acoustic simulation}",
	journal = "Signal, Image and Video Processing",
	note = "{DOI = 10.1007/s11760-012-0387-0}",
	year = 2012,
	month = "Oct."
}

  12. A Primavera, M Gasparini, S Cecchi, L Romoli and F Piazza. Hybrid Reverberation Algorithm: a Practical Approach. In AIA-DAGA Conference . 2013, . BibTeX

    @inproceedings{primavera-aia-13,
	title = "{Hybrid Reverberation Algorithm: a Practical Approach}",
	author = "Primavera, A. and Gasparini, M. and Cecchi, S. and Romoli, L. and Piazza, F.",
	booktitle = "AIA-DAGA Conference",
	volume = "",
	address = "Merano, Italy",
	month = "Mar.",
	year = 2013,
	pages = ""
}

  13. A Primavera, S Cecchi, F Piazza, J Li and Y Yan. Hybrid Reverberator Using Multiple Impulse Responses for Audio Rendering Improvement. In Proc. of IIHMSP . 2013, . BibTeX

    @inproceedings{primavera-iihmsp-13,
	title = "{Hybrid Reverberator Using Multiple Impulse Responses for Audio Rendering Improvement}",
	author = "Primavera, A. and Cecchi, S. and Piazza, F. and Li, J. and Yan, Y.",
	booktitle = "Proc. of IIHMSP",
	volume = "",
	address = "Beijing, China",
	month = "Oct.",
	year = 2013,
	pages = ""
}

  14. A Primavera, S Cecchi, Li Junfeng and F Piazza. Objective and Subjective Investigation on a Novel Method for Digital Reverberator Parameters Estimation. IEEE Trans. Audio, Speech and Language Processing 22(2):441-452, 2014. BibTeX

    @article{primavera-jasl-13,
	author = "Primavera, A. and Cecchi, S. and Junfeng, Li and Piazza, F.",
	title = "{Objective and Subjective Investigation on a Novel Method for Digital Reverberator Parameters Estimation}",
	journal = "IEEE Trans. Audio, Speech and Language Processing",
	volume = 22,
	number = 2,
	pages = "441-452",
	year = 2014,
	month = "Feb."
}

  15. A Primavera, S Cecchi, F Piazza, J Li and Y Yan. An efficient time varying hybrid reverberator for room acoustic simulation. In Proc. 2nd IEEE China Summit and International Conference on Signal and Information Processing. July 2014, . BibTeX

    @inproceedings{primavera-chinasip-14,
	title = "{An efficient time varying hybrid reverberator for room acoustic simulation}",
	author = "Primavera, A. and Cecchi, S. and Piazza, F. and Li, J. and Yan, Y.",
	booktitle = "Proc. 2nd {IEEE} China Summit and International Conference on Signal and Information Processing",
	address = "Xi'an, China",
	year = 2014,
	month = "Jul",
	pages = "",
	notes = "accepted for presentation"
}