Reverberation Time Errors From Frequency Domain Filtering
DOI:
https://doi.org/10.18372/1990-5548.86.20625Keywords:
reverberation time, frequency dependence, spectral domain filtering, amplitude-frequency response, Tukey window, bias of estimateAbstract
Information about the frequency dependence of reverberation time is essential for addressing several tasks, including mitigating the impact of reverberation on speech quality and intelligibility, as well as assessing intelligibility using the indirect modulation method. To obtain this information, the room impulse response must be filtered using a bank of octave or one-third-octave filters. This paper analyzes the influence of frequency bandwidth and the shape of the filter’s amplitude-frequency response on the bias of T20, T30, EDT, and T10 estimates of the T60 reverberation time. The analysis assumes that filtering is implemented in the spectral domain by zeroing the spectral components of the RIR outside the desired passband, and that the filter's amplitude-frequency response has the shape of a Tukey window. The results show that the use of filters with a rectangular amplitude-frequency response (Tukey window with parameter r = 0) is undesirable, as it leads to significant bias in the T20, T30, EDT, and T10 estimates. This bias can reach 60–100% for reverberation times in the range of T60 = 0.4–1.2 s. Using filters with a Tukey window shape and r = 1 reduces the bias to no more than 4% when filtering room impulse responses with octave filters at center frequencies f0 ≥ 125 Hz. For one-third-octave filters with f0 ≥ 25 Hz, a similar level of bias is observed for T20 and T30 estimates. For EDT and T10 estimates, a bias of no more than 4% is achieved within the T60 = 0.6–1.2 s range.
References
ISO 3382-1:2009 Acoustics – Measurement of room acoustic parameters – Part 1: Performance spaces, Geneva: International Organization for Standardization, 2009.
ISO 3382-2:2008 Acoustics – Measurement of room acoustic parameters – Part 2: Reverberation time in ordinary rooms, Geneva: International Organization for Standardization, 2008.
IEC 61260-1-2014 Electroacoustics – Octave-band and fractional-octaveband filters, European Committee for Electrotechnical Standardization, 2014.
M. Schroeder, “New method of measuring reverberation time,” J. Acoust. Soc. Amer. 37, 1965, pp. 409–412. https://doi.org/10.1121/1.1909343
R. Kurer and U. Kurze, "Integrationsverfahren zur Nachhallauswertung," ("Integration Method for the Evaluation of Reverberation Measurement"), Acustica, vol. 19 (1967/68), pp. 313–322.
K. Bordlund, "On the use of the integrated impulse response method for laboratory reverberation measurements," Journal of Sound and Vibration, 56(3), 1978, pp. 341–362. https://doi.org/10.1016/S0022-460X(78)80152-7
W. Chu, "Comparison of Reverberation Measurements Using Schroeder's Impulse Method and Decay-Curve Averaging Method," J. Acoust. Soc. Am., vol. 63, 1978, pp. 1444–1450. https://doi.org/10.1121/1.381889
J. Davy, “The variance of decay rates in reverberation rooms,” Acustica, vol.43, no.1, pp. 51–56, 1979.
J. Davy, “The variance of impulse decays,” Acustica, vol. 44, no.1, pp. 51–56. 1980. https://doi.org/10.1109/ACOUSTICS.2018.8502277.
ANSI/ASA S12.60-2010/Part 1 American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 1: Permanent Schools.
Acoustic design of schools: performance standards. Building bulletin 93. UK Department for Education, 2015. Availabe in: https://assets.publishing.service.gov.uk/media/5a8170d3e5274a2e8ab54012/BB93_February_2015.pdf
H. Löllmann, “Estimation of the Reverberation Time in Noisy Environments,” In Proceedings of the International Workshop on Acoustic Echo and Noise Control (IWAENC). Seattle, US, 2008. Available in: https://www.iwaenc.org/proceedings/2008/contents/papers/9033.pdf
H. Steeneken and T. Houtgast, “Basics of the STI measuring method,” in Past, present and future of the Speech Transmission Index. Soesterberg: TNO Human Factors, 2002.
A. Prodeus and A. Naida, "A Two-Stage Algorithm for Determining the Truncation Time and Reverberation Time," 2024 IEEE 7th International Conference Actual Problems of Unmanned Aerial Vehicles Developments (APUAVD), October 22-24, 2024, Kyiv, Ukraine. https://doi.org/10.1109/APUAVD64488.2024.10765903
A. Prodeus and A. Naida, "Reverberation Time Estimation Algorithm Accuracy," Electronics and Control Systems, 2025. no. 1(83), pp. 9–17. https://doi.org/10.18372/1990-5548.83.19362
Downloads
Published
Issue
Section
License
Authors who publish with this journal agree to the following terms:
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
