Bandwidth extension of narrowband speech

Recently, 4G mobile phone systems have been designed to process wideband speech signals whose sampling frequency is 16 kHz. However, most part of mobile and classical phone network, and current 3G mobile phones, still process narrowband speech signals whose sampling frequency is 8 kHz. During next future, all these systems must be living together. Therefore, sometimes a wideband speech signal (with a bandwidth up to 7,2 kHz) should be estimated from an available narrowband one (whose frequency band is 300-3400 Hz). In this work, different techniques of audio bandwidth extension have been implemented and evaluated. First, a simple non-model-based algorithm (interpolation algorithm) has been implemented. Second, a model-based algorithm (linear mapping) have been designed and evaluated in comparison to previous one. Several CMOS (Comparison Mean Opinion Score) [6] listening tests show that performance of Linear Mapping algorithm clearly overcomes the other one. Results of these tests are very close to those corresponding to original wideband speech signal.Postprint (published version

Buscant materials adients per insonoritzar un local per fer-hi música

Es presenta un treball de recerca en el qual s'han estudiat diferents materials de construcció per tal d'analitzar quin és el que millor atenua el so. El treball experimental s'ha basat en la construcció d'un conjunt de capses, folrades amb diferents materials que reprodueixen un local on s'assaja amb un instrument musical, i en la mesura del nivell d'intensitat sonora emès per una font sonora tant a l'interior com a l'exterior de les capses

Extensión del ancho de banda de señales de voz de banda estrecha

[ANGLÈS] Many telecommunication systems and internet networks (VoIP systems) transmit narrowband speech signals, i.e. signals with a frequency band from 300-3400 Hz, and a sampling frequency of 8 kHz. In order to improve speech quality, it is desirable to artificially increase the bandwidth on both sides of the frequency spectrum. Typically, we would like to transform narrowband speech to wideband speech with approximately 8 kHz bandwidth, and 16 kHz sampling frequency. In this final degree project, many different techniques of audio bandwidth extension have been developed, from less to more complexity and the improvement of the quality regarding the original signal has been analysed by audio testing. First, nonmodel-based algorithms have been developed, like oversampling and imaging that make use of the spectral components that occur when upsampling. Next model-based algorithm like linear mapping has been implemented. After all, both methods have been compared with a CMOS listening test to show the subjective differences between them.[CASTELLÀ] La mayoría de los sistemas de transmisión de voz en telecomunicaciones y redes de internet (VoIP) transmiten las señales en banda estrecha, es decir, señales cuyas componentes frecuenciales oscilan entre los 300 Hz y los 3400 Hz (utilizando una frecuencia de muestreo de 8 kHz), Para poder mejorar la calidad auditiva de estos señales, existen técnicas que permiten aumentar este ancho de banda hasta los 8000 Hz con una frecuencia de muestreo de 16 kHz. En este trabajo de fin de grado se han analizado diferentes técnicas de ensanchado del ancho de banda sobre señales de banda estrecha, de menor a mayor complejidad, y se han analizado auditivamente las mejoras en la claridad del señal respecto del señal original. Primero, usando sistemas no basados en el modelo fuente-filtro, como por ejemplo, las réplicas en frecuencia que aparecen cuando se interpola un señal. Después, con técnicas basadas en el modelo fuente-filtro como la modulación en frecuencia para el ensanchamiento del señal de excitación o el mapeo lineal para estimar el envolvente espectral del señal. También se han realizado tests auditivos CMOS para mostrar las diferencias subjetivas entre ambas técnicas, además de calcular la distancia Itakura para tener una referencia de una distancia objetiva.[CATALÀ] La majoria dels sistemes de transmissió de veu en telecomunicacions i xarxes d’internet (VoIP) transmeten els senyals en banda estreta, és a dir, senyals amb components freqüencials entre els 300 Hz i els 3400 Hz (utilitzant una freqüència de mostreig de 8 kHz). Per a poder millorar la qualitat auditiva d’aquests senyals, existeixen tècniques que permeten augmentar aquest ample de banda fins als 8000 Hz amb una freqüència de mostreig de 16 kHz. En aquest treball de fi de grau, s’han analitzat diferents tècniques d’eixamplament de l’ample de banda de senyals de banda estreta, de menor a major complexitat i s’ha analitzat auditivament la millora en la claredat del senyal respecte al senyal original. Primer, utilitzant sistemes no basats en el model font-filtre, com per exemple, les rèpliques en freqüència que apareixen quan interpolem un senyal. Després, amb altres tècniques basades en el model font-filtre com per exemple la modulació en freqüència per a l’eixamplament de l’excitació del senyal o el mapeig lineal per a eixamplar l’envolupant espectral del senyal. També s’ha realitzat un test auditiu CMOS per a mostrar les diferències subjectives entre ambdues tècniques. També s'ha calculat la distància Itakura entre els senyals per a tenir una referència d'una distància objectiva entre els senyals

Extensión del ancho de banda de señales de voz de banda estrecha

[ANGLÈS] Many telecommunication systems and internet networks (VoIP systems) transmit narrowband speech signals, i.e. signals with a frequency band from 300-3400 Hz, and a sampling frequency of 8 kHz. In order to improve speech quality, it is desirable to artificially increase the bandwidth on both sides of the frequency spectrum. Typically, we would like to transform narrowband speech to wideband speech with approximately 8 kHz bandwidth, and 16 kHz sampling frequency. In this final degree project, many different techniques of audio bandwidth extension have been developed, from less to more complexity and the improvement of the quality regarding the original signal has been analysed by audio testing. First, nonmodel-based algorithms have been developed, like oversampling and imaging that make use of the spectral components that occur when upsampling. Next model-based algorithm like linear mapping has been implemented. After all, both methods have been compared with a CMOS listening test to show the subjective differences between them.[CASTELLÀ] La mayoría de los sistemas de transmisión de voz en telecomunicaciones y redes de internet (VoIP) transmiten las señales en banda estrecha, es decir, señales cuyas componentes frecuenciales oscilan entre los 300 Hz y los 3400 Hz (utilizando una frecuencia de muestreo de 8 kHz), Para poder mejorar la calidad auditiva de estos señales, existen técnicas que permiten aumentar este ancho de banda hasta los 8000 Hz con una frecuencia de muestreo de 16 kHz. En este trabajo de fin de grado se han analizado diferentes técnicas de ensanchado del ancho de banda sobre señales de banda estrecha, de menor a mayor complejidad, y se han analizado auditivamente las mejoras en la claridad del señal respecto del señal original. Primero, usando sistemas no basados en el modelo fuente-filtro, como por ejemplo, las réplicas en frecuencia que aparecen cuando se interpola un señal. Después, con técnicas basadas en el modelo fuente-filtro como la modulación en frecuencia para el ensanchamiento del señal de excitación o el mapeo lineal para estimar el envolvente espectral del señal. También se han realizado tests auditivos CMOS para mostrar las diferencias subjetivas entre ambas técnicas, además de calcular la distancia Itakura para tener una referencia de una distancia objetiva.[CATALÀ] La majoria dels sistemes de transmissió de veu en telecomunicacions i xarxes d’internet (VoIP) transmeten els senyals en banda estreta, és a dir, senyals amb components freqüencials entre els 300 Hz i els 3400 Hz (utilitzant una freqüència de mostreig de 8 kHz). Per a poder millorar la qualitat auditiva d’aquests senyals, existeixen tècniques que permeten augmentar aquest ample de banda fins als 8000 Hz amb una freqüència de mostreig de 16 kHz. En aquest treball de fi de grau, s’han analitzat diferents tècniques d’eixamplament de l’ample de banda de senyals de banda estreta, de menor a major complexitat i s’ha analitzat auditivament la millora en la claredat del senyal respecte al senyal original. Primer, utilitzant sistemes no basats en el model font-filtre, com per exemple, les rèpliques en freqüència que apareixen quan interpolem un senyal. Després, amb altres tècniques basades en el model font-filtre com per exemple la modulació en freqüència per a l’eixamplament de l’excitació del senyal o el mapeig lineal per a eixamplar l’envolupant espectral del senyal. També s’ha realitzat un test auditiu CMOS per a mostrar les diferències subjectives entre ambdues tècniques. També s'ha calculat la distància Itakura entre els senyals per a tenir una referència d'una distància objectiva entre els senyals

Bandwidth extension of narrowband speech

Recently, 4G mobile phone systems have been designed to process wideband speech signals whose sampling frequency is 16 kHz. However, most part of mobile and classical phone network, and current 3G mobile phones, still process narrowband speech signals whose sampling frequency is 8 kHz. During next future, all these systems must be living together. Therefore, sometimes a wideband speech signal (with a bandwidth up to 7,2 kHz) should be estimated from an available narrowband one (whose frequency band is 300-3400 Hz). In this work, different techniques of audio bandwidth extension have been implemented and evaluated. First, a simple non-model-based algorithm (interpolation algorithm) has been implemented. Second, a model-based algorithm (linear mapping) have been designed and evaluated in comparison to previous one. Several CMOS (Comparison Mean Opinion Score) [6] listening tests show that performance of Linear Mapping algorithm clearly overcomes the other one. Results of these tests are very close to those corresponding to original wideband speech signal

Innovation tools for Chem-E-Car Competition in Spain

Desarrollo de herramientas docentes para la adquisición de la capacidad de controlar de forma segura una reacción química, concibiendo, diseñando y ejecutando un sistema cumpliendo los estándares de seguridad y medioambientales. Las herramientas desarrolladas son de aplicación a un posible implantación de la competición desarrollada por AIChE: "Chem-E-Car".Development of teaching tools to acquire the ability to safely control a chemical reaction, conceiving, designing and implementing a system meeting the safety and environmental standards. The tools developed are designed for a possible implementation of the competition developed by AIChE, "Chem-E-Car".Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasFALSEsubmitte

Switching TNF antagonists in patients with chronic arthritis: An observational study of 488 patients over a four-year period

The objective of this work is to analyze the survival of infliximab, etanercept and adalimumab in patients who have switched among tumor necrosis factor (TNF) antagonists for the treatment of chronic arthritis. BIOBADASER is a national registry of patients with different forms of chronic arthritis who are treated with biologics. Using this registry, we have analyzed patient switching of TNF antagonists. The cumulative discontinuation rate was calculated using the actuarial method. The log-rank test was used to compare survival curves, and Cox regression models were used to assess independent factors associated with discontinuing medication. Between February 2000 and September 2004, 4,706 patients were registered in BIOBADASER, of whom 68% had rheumatoid arthritis, 11% ankylosing spondylitis, 10% psoriatic arthritis, and 11% other forms of chronic arthritis. One- and two-year drug survival rates of the TNF antagonist were 0.83 and 0.75, respectively. There were 488 patients treated with more than one TNF antagonist. In this situation, survival of the second TNF antagonist decreased to 0.68 and 0.60 at 1 and 2 years, respectively. Survival was better in patients replacing the first TNF antagonist because of adverse events (hazard ratio (HR) for discontinuation 0.55 (95% confidence interval (CI), 0.34-0.84)), and worse in patients older than 60 years (HR 1.10 (95% CI 0.97-2.49)) or who were treated with infliximab (HR 3.22 (95% CI 2.13-4.87)). In summary, in patients who require continuous therapy and have failed to respond to a TNF antagonist, replacement with a different TNF antagonist may be of use under certain situations. This issue will deserve continuous reassessment with the arrival of new medications. © 2006 Gomez-Reino and Loreto Carmona; licensee BioMed Central Ltd

Development, validation, and prognostic evaluation of a risk score for long-term liver-related outcomes in the general population: a multicohort study

Liver cirrhosis is a major cause of death worldwide. Cirrhosis develops after a long asymptomatic period of fibrosis progression, with the diagnosis frequently occurring late, when major complications or cancer develop. Few reliable tools exist for timely identification of individuals at risk of cirrhosis to allow for early intervention. We aimed to develop a novel score to identify individuals at risk for future liver-related outcomes. We derived the LiverRisk score from an international prospective cohort of individuals from six countries without known liver disease from the general population, who underwent liver fibrosis assessment by transient elastography. The score included age, sex, and six standard laboratory variables. We created four groups: minimal risk, low risk, medium risk, and high risk according to selected cutoff values of the LiverRisk score (6, 10, and 15). The model's discriminatory accuracy and calibration were externally validated in two prospective cohorts from the general population. Moreover, we ascertained the prognostic value of the score in the prediction of liver-related outcomes in participants without known liver disease with median follow-up of 12 years (UK Biobank cohort). We included 14 726 participants: 6357 (43·2%) in the derivation cohort, 4370 (29·7%) in the first external validation cohort, and 3999 (27·2%) in the second external validation cohort. The score accurately predicted liver stiffness in the development and external validation cohorts, and was superior to conventional serum biomarkers of fibrosis, as measured by area under the receiver-operating characteristics curve (AUC; 0·83 [95% CI [0·78-0·89]) versus the fibrosis-4 index (FIB-4; 0·68 [0·61-0·75] at 10 kPa). The score was effective in identifying individuals at risk of liver-related mortality, liver-related hospitalisation, and liver cancer, thereby allowing stratification to different risk groups for liver-related outcomes. The hazard ratio for liver-related mortality in the high-risk group was 471 (95% CI 347-641) compared with the minimal risk group, and the overall AUC of the score in predicting 10-year liver-related mortality was 0·90 (0·88-0·91) versus 0.84 (0·82-0·86) for FIB-4. The LiverRisk score, based on simple parameters, predicted liver fibrosis and future development of liver-related outcomes in the general population. The score might allow for stratification of individuals according to liver risk and thus guide preventive care. None. [Abstract copyright: Copyright © 2023 Elsevier Ltd. All rights reserved.