scholarly journals Audio dynamics automatic equalization inspired by visual perception

Author(s):  
Luca A. Ludovico ◽  
Giorgio Presti ◽  
Alessandro Rizzi

AbstractThis paper explores the behavior of an algorithm called Audio Dynamics Automatic Equalization (ADAE). This algorithm has been inspired by research carried out in the context of image restoration: it is the adaptation of a contrast and color unsupervised equalizer for images, called Automatic Color Equalization (ACE), into the audio domain. Beside testing if the domain shift from image to audio processing can bring some interesting result, this work also investigates if ADAE behaves like already-known technologies for audio manipulation and restoration. To this end, after a description of the original and the derived algorithms, quantitative test are carried out using typical analyses from the Sound and Music Computing literature, such as frequency response, transfer function, and harmonic distortion. Finally, the paper discusses how the algorithm introduces dynamic range adjustments and non-linear distortions, thus behaving like a dynamics processor, a harmonic exciter, and a waveshaper.

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 734
Author(s):  
Karolis Kiela ◽  
Marijan Jurgo ◽  
Vytautas Macaitis ◽  
Romualdas Navickas

This article presents a wideband reconfigurable integrated low-pass filter (LPF) for 5G NR compatible software-defined radio (SDR) solutions. The filter uses Active-RC topology to achieve high linearity performance. Its bandwidth can be tuned from 2.5 MHz to 200 MHz, which corresponds to a tuning ratio of 92.8. The order of the filter can be changed between the 2nd, 4th, or 6th order; it has built-in process, voltage, and temperature (PVT) compensation with a tuning range of ±42%; and power management features for optimization of the filter performance across its entire range of bandwidth tuning. Across its entire order, bandwidth, and power configuration range, the filter achieves in-band input-referred third-order intercept point (IIP3) between 32.7 dBm and 45.8 dBm, spurious free dynamic range (SFDR) between 63.6 dB and 79.5 dB, 1 dB compression point (P1dB) between 9.9 dBm and 14.1 dBm, total harmonic distortion (THD) between −85.6 dB and −64.5 dB, noise figure (NF) between 25.9 dB and 31.8 dB and power dissipation between 1.19 mW and 73.4 mW. The LPF was designed and verified using 65 nm CMOS process; it occupies a 0.429 mm2 area of silicon and uses a 1.2 V supply.


2013 ◽  
Vol 473 ◽  
pp. 50-53
Author(s):  
Jie Lin ◽  
Fei Yan Mu

A high accuracy BiCMOS sample and hold (S/H) circuit employed in the front end of a12bit 10 MS/s Pipeline ADC is presented. To reduce the nonlinearity error cause by the sampling switch, a signal dependent clock bootstrapping system is introduced. It is implemented using 0.6 um BiCMOS process. An 88.77 dB spurious-free dynamic range (SFDR), and a -105.20 dB total harmonic distortion (THD) are obtained.


2008 ◽  
Vol 3 (2) ◽  
pp. 021207 ◽  
Author(s):  
Duarte Valério ◽  
Manuel Duarte Ortigueira ◽  
José Sá da Costa

2020 ◽  
Vol 10 (6) ◽  
pp. 2070
Author(s):  
Ricardo San Martín ◽  
Pablo Tello ◽  
Ana Valencia ◽  
Asier Marzo

Parametric loudspeakers can generate a highly directional beam of sound, having applications in targeted audio delivery. Audible sound modulated into an ultrasonic carrier will get self-demodulated along the highly directive beam due to the non-linearity of air. This non-linear demodularization should be compensated to reduce audio distortion, different amplitude modulation techniques have been developed during the last years. However, some studies are only theoretical whereas others do not analyze the audio distortion in depth. Here, we present a detailed experimental evaluation of the frequency response, harmonic distortion and intermodulation distortion for various amplitude modulation techniques applied with different indices of modulation. We used a simple method to measure the audible signal that prevents the saturation of the microphones when the high levels of the ultrasonic carrier are present. This work could be useful for selecting predistortion techniques and indices of modulation for regular parametric arrays.


1994 ◽  
Vol 158 ◽  
pp. 61-69 ◽  
Author(s):  
Robert J. Hanisch ◽  
Richard L. White

The spherical aberration in the primary mirror of the Hubble Space Telescope causes more than 80% of the light from a point source to be spread into a halo of radius of 2–3 arcsec. The point spread function (PSF) is both time variant (resulting from spacecraft jitter and desorption of the secondary mirror support structure) and space variant (owing to the Cassegrain repeater optics in the Wide Field / Planetary Camera). A variety of image restoration algorithms have been utilized on HST data with some success, although optimal restorations require better modeling of the PSF and the development of efficient restoration algorithms that accommodate a spacevariant PSF. The first HST servicing mission (December 1993) will deploy a corrective optics system for the Faint Object Camera and the two spectrographs and a second generation WF/PC with internal corrective optics. As simulations demonstrate, however, the restoration algorithms developed now for aberrated images will be very useful for removing the remaining diffraction features and optimizing dynamic range in post-servicing mission data.


1986 ◽  
Vol 108 (4) ◽  
pp. 368-371 ◽  
Author(s):  
Jium-Ming Lin ◽  
Kuang-Wei Han

In this brief note, the effects of model reduction on the stability boundaries of control systems with parameter variations, and the limit-cycle characteristics of nonlinear control systems are investigated. In order to reduce these effects, a method of model reduction is used which can approximate the original transfer function at S=0, S=∞, and also match some selected points on the frequency response curve of the original transfer function. Examples are given, and comparisons with the methods given in current literature are made.


2015 ◽  
Vol 24 (03) ◽  
pp. 1550032 ◽  
Author(s):  
Siwan Dong ◽  
Minjie Liu ◽  
Zhangming Zhu ◽  
Yintang Yang

This paper presents a new bootstrapped switch with high speed and low nonlinear distortion. Instead of fixed voltage, the gate-to-source voltage of switch varies with input to implement first-order body effect compensation. Post-layout simulations have been done in standard 0.18-μm CMOS process at 1.8 V, and results indicate that at 200 MHz sample rate, a peak signal-to-noise-and-distortion ratio (SNDR) of 98.4 dB, spurious-free dynamic range (SFDR) of 105.7 dB and total harmonic distortion (THD) of -104.9 dB can be acquired. For input frequency up to the 60 MHz frequency, proposed structure maintains |THD| over 85 dB, SFDR better than 86 dB, respectively.


1990 ◽  
Vol 33 (4) ◽  
pp. 676-689 ◽  
Author(s):  
David A. Fabry ◽  
Dianne J. Van Tasell

The Articulation Index (AI) was used to evaluate an “adaptive frequency response” (AFR) hearing aid with amplification characteristics that automatically change to become more high-pass with increasing levels of background noise. Speech intelligibility ratings of connected discourse by normal-hearing subjects were predicted well by an empirically derived AI transfer function. That transfer function was used to predict aided speech intelligibility ratings by 12 hearing-impaired subjects wearing a master hearing aid with the Argosy Manhattan Circuit enabled (AFR-on) or disabled (AFR-off). For all subjects, the AI predicted no improvements in speech intelligibility for the AFR-on versus AFR-off condition, and no significant improvements in rated intelligibility were observed. The ability of the AI to predict aided speech intelligibility varied across subjects. However, ratings from every hearing-impaired subject were related monotonically to AI. Therefore, AI calculations may be used to predict relative—but not absolute—levels of speech intelligibility produced under different amplification conditions.


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