Speech-AEPs

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The main objective of this project is the development of novel methods for recording auditory evoked potentials (AEPs) elicited by natural speech. Recording speech-elicited AEP responses is challenging and requires: (1) advanced signal processing algorithms that enable the simultaneous deconvolution of multiple overlapping AEPs (i.e., multi-response deconvolution); (2) methods for reducing different noise artifacts during EEG acquisition; (3) methods for appropriate categorization of speech events to be considered in multi-response deconvolution; and (4) well-defined protocols for recording and deconvolution of speech-elicited AEP responses for future research and clinical applications. This project considers the specific objectives below.

1. Develop novel signal processing algorithms that enable fast multi-response deconvolution, appropriate for estimating overlapping transient responses elicited by speech.
2. Develop novel algorithms that attenuate different noise sources, typically present in recorded electroencephalograms, including blink-artifacts and artifacts derived from the electrical network.
3. Define adequate categories of speech-elicited AEPs based on characteristics of the speech stimulus, e.g. “voice-onset”, “speech envelope”, “glottal closure instants”, etc.
4. Analyse and interpret the morphology of the speech-elicited AEPs obtained for different categories in order to advance knowledge in how the central and peripherical human auditory system encodes and process speech.
5. Design easy-to-use protocols for recording and analysis speech-elicited AEPs to facilitate the use of these technologies by other researchers and clinicians.

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Journal articles

• de la Torre A, Alvarez IM, Muñoz-Orellana, JA. A phase-demodulation based time drift compensation for the reduction of the 50/60 Hz power line interference in biopotentials. Biomedical Signal Processing & Control (2026) 115. 109423. doi: 10.1016/j.bspc.2025.109423
  Open access
  Click on the “View PDF” to download the manuscript.
  Click on “Supplementary Data” to download the Supplementary Material in a zip file. This material includes a detailed pdf document as well as Matlab/Octave code implementing the proposed procedure.
• de la Torre A, Sanchez I, Alvarez IM, Segura JC, Valderrama JT, Muller N, Vargas JL. Multi-response deconvolution of auditory evoked potentials in a reduced representation space. Journal of the Acoustical Society of America (2024) 155, 3639–3653. doi: 10.1121/10.0026228.
  Open access
  Click on “PDF” to download the manuscript.
  Click on “Views / Supplementary Data” to download the Supplementary Material in a zip file. This material includes a detailed pdf document as well as Matlab/Octave code implementing the proposed procedure.
• Valderrama JT, de la Torre A, McAlpine D. The hunt for hidden hearing loss in humans: From preclinical studies to effective interventions. Frontiers in Neuroscience (2022) 16, 1000304, 13p. doi: 10.3389/fnins.2022.1000304. [Download]
• Martinez M, Valderrama JT, Alvarez IM, de la Torre A, Vargas JL. Auditory brainstem responses obtained with randomised stimulation level. International Journal of Audiology (2022), available online at 10.1080/14992027.2022.2047233. [Download]
• de la Torre A, Valderrama JT, Segura JC, Alvarez IM. Subspace-constrained deconvolution of auditory evoked potentials. Journal of the Acoustical Society of America (2022) 151, 3745-3757. doi: 10.1121/10.0011423. [Download]

Patents

• Title: An improved procedure for reduction of quasi-periodic interferences
  Inventors: de la Torre A, Alvarez IM, Muñoz-Orellana JA.
  Applicant: University of Granada (Spain)
  Application number: EP25166854.7 (European Application), ESP202430935 (Spanish Application)
  Priority date: 12/11/2024
  Status: Under review
  Contact: [Principal Investigator] Prof Ángel de la Torre Vega (atv@ugr.es). [University of Granada] Knowledge Transfer Office (otri@ugr.es).
• Title: Devices and methods for common mode noise reduction in biopotential acquisitions
  Inventors: de la Torre A, Alvarez IM, Segura JC, Valderrama JT, Palma AJ, Carvajal MA, Pousibet A
  Applicant: University of Granada (Spain)
  Application number: EP4461221A1 (European Application)
  Publication date: 13/11/2024
  Status: Withdrawn
  Contact: [Principal Investigator] Prof Ángel de la Torre Vega (atv@ugr.es). [University of Granada] Knowledge Transfer Office (otri@ugr.es).

Conference contributions

• de la Torre A, Alvarez IM, Muller N, Chiquero F, Martin-Lagos J, Vargas JL. Potenciales auditivos evocados con voz sintética: Entendiendo las respuestas transitorias tempranas y tardías asociadas a los pulsos glotales y a los fonemas. Podium presentation at the 76 Congreso Nacional de la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC), Madrid, España (October 22-25, 2025). [Abstract, Presentation, Slides description, Conference summary]
• Muller N, de la Torre A, Chiquero F, Alvarez IM, Martin-Lagos J, Vargas JL. Respuestas evocadas auditivas con estimulación multinivel para la determinación ultra-precisa de los umbrales de audición. Podium presentation at the 76 Congreso Nacional de la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC), Madrid, España (October 22-25, 2025). [Abstract, Presentation, Slides description, Conference summary]
• Chiquero F, Alvarez IM, Muller N, Martin-Lagos J, Vargas JL, de la Torre A. Evaluación objetiva de la percepción en ruido específica de la frecuencia basada en potenciales evocados auditivos. Podium presentation at the 76 Congreso Nacional de la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC), Madrid, España (October 22-25, 2025). [Abstract, Presentation, Slides description, Conference summary]
• de la Torre A, Alvarez IM, Muñoz-Orellana JA, Martin-Lagos J, Vargas JL. Diseño y demostración de un sistema de registro de potenciales evocados auditivos de bajo coste basado en electrónica de consumo: aplicación para divulgación de conceptos audiológicos en colegios y museos de ciencia. Poster presentation at the 76 Congreso Nacional de la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC), Madrid, España (October 22-25, 2025). [Abstract, Poster, Poster description, Conference summary]
• de la Torre A, Alvarez IM, Raya M, Muñoz-Orellana JA, Martin-Lagos J, Torres-Lara JA. Design and demonstration of a low-cost AEP recording system based on consumer electronics: Application for disseminating audiological concepts in schools and science museums. Podium presentation at the International Workshop on Sound Signal Processing Applications (IWSSPA), Rota, Spain (July 8-11, 2025). [Abstract, Presentation, Slides description, Conference summary]
• Chiquero F, Alvarez IM, Müller N, de la Torre A, Martín-Lagos J, Vargas JL. Frequency specific objective AEP-based assessment of hearing perception in noise. Podium presentation at the XXIX International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Boulder, Colorado, EEUU (June 14-18, 2025). [Abstract, Presentation, Slides description, Conference summary]
• de la Torre A, Alvarez IM, Muñoz-Orellana JA, Martín-Lagos J, López-Pérez L, Torres-Lara JA. Reduction of the power line interference in a single-channel AEP recording system based on low cost consumer electronics: application for dissemination of audiology concepts in schools and at a science museum. Poster presentation at the XXIX International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Boulder, Colorado, EEUU (June 14-18, 2025). [Abstract, Poster, Poster description, Conference summary]
• de la Torre A, Alvarez IM, Müller N, Chiquero F, Martín-Lagos J, Vargas JL. Understanding early and late transient responses to speech: experiments using synthetic speech. Poster presentation at the XXIX International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Boulder, Colorado, EEUU (June 14-18, 2025). [Abstract, Poster, Poster description, Conference summary]
• Müller N, de la Torre A, Chiquero F, Alvarez IM, Martín-Lagos J, Vargas JL. Auditory evoked responses of the complete auditory pathway using structured stimulation sequences. Poster presentation at the XXIX International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Boulder, Colorado, EEUU (June 14-18, 2025). [Abstract, Poster, Poster description, Conference summary]
• de la Torre A, Valderrama JT, Alvarez IM, Segura, JC, Vargas JL, Palma AJ, Carvajal MA, Pousibet A. Live demonstration of a portable, affordable, and versatile auditory evoked potentials recording system mostly based on off-the-shelf electronics. Podium presentation and live demonstration at the XXVIII International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Cologne, Germany (September 15-19, 2023). [Abstract, Presentation, Slides description, Temporary Supplemental file (583 MB, available until 02/12/2023), Permanent Supplemental file (6 MB, Binary files and detailed figures excluded), Conference summary]
• de la Torre A, Sanchez I, Valderrama JT, Alvarez IM, Segura JC, Muller N, Vargas JL. Simultaneous deconvolution of multiple auditory evoked potentials in a reduced representation space. Podium presentation at the XXVIII International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Cologne, Germany (September 15-19, 2023). [Abstract, Presentation, Slides description, Conference summary]
• Valderrama JT, de la Torre A, Alvarez IM, Segura JC, Vargas JL. Deconvolution for flexible recording of transient evoked potentials. Podium presentation at the XXVIII International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Cologne, Germany (September 15-19, 2023). [Abstract, Presentation, Slides description, Conference summary]
• Valderrama JT, de la Torre A, Alvarez IM, Segura JC, Vargas JL. En la búsqueda de nuevos biomarcadores de la pérdida de audición oculta. Podium presentation at the XIX National Congress of Audiology of the Spanish Association of Audiology (AEDA), Madrid, Spain (June 15-17, 2023). [Presentation]
• de la Torre A. EEG Demonstration: Recording evoked potentials beyond the laboratory. Podium presentation & live demonstration at the 2023 International Workshop on Advances in Audiology, Salamanca, Spain (May 25-27, 2023). [Abstract, Presentation, Demonstration]
• Valderrama JT. New avenues for recording auditory evoked potentials. Podium presentation at the 2023 International Workshop on Advances in Audiology, Salamanca, Spain (May 25-27, 2023). [Abstract, Presentation]
• Martinez M, Alvarez IM, Valderrama JT, de la Torre A, Vargas JL. Clinical value of auditory evoked potentials obtained with randomised stimulation <<Valor clínico de potenciales evocados auditivos obtenidos con niveles de estimulación aleatorizados>>. Podium presentation at the 73^rd Congress of the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC), Las Palmas de Gran Canaria, Spain (Oct 13-15, 2022). [Abstract, Presentation]
• Martinez M, Alvarez IM, Valderrama JT, de la Torre A, Vargas JL. The transient response to inter-aural time differences <<Respuesta transitoria a las diferencias interaurales de tiempo>>. Podium presentation at the 73^rd Congress of the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC), Las Palmas de Gran Canaria, Spain (Oct 13-15, 2022). [Abstract, Presentation]
• Martinez M, Alvarez IM, Valderrama JT, Vargas JL, de la Torre A. Recording auditory brainstem responses with randomized stimulation level. Podium presentation at the XXVII International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, online Forum (June 14 – July 9, 2021). [Abstract, Presentation]
• Martinez M, Valderrama JT, Alvarez IM, Vargas JL, de la Torre A. The transient response to interaural time differences. Podium presentation at the XXVII International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, online Forum (June 14 – July 9, 2021). [Abstract, Presentation]
• Valderrama JT, de la Torre A, Van Dun B, Segura JC. Towards the recording of brainstem and cortical evoked responses from the fine structure of natural speech. Podium presentation at the XXVI International Evoked Response Audiometry Study Group (IERASG) Biennial Symposium, Sydney, Australia (June 30 – July 4, 2019). [Abstract, Presentation]

Students supervision

• Phd candidate: Francisco Antonio Chiquero Ortiz
  Title: Potenciales evocados auditivos en respuesta a estímulos específicos de la frecuencia. Aplicaciones clínicas
  Supervisors: Isaac Manuel Álvarez Ruiz y José Luis Vargas Fernández
  Department: Programa de Doctorado en Medicina y Salud Pública, University of Granada
  Sponsorship: [Sponsor 1] P21.00152 (E-HHL-D), Andalusian Plan for Research, Development, and Innovation (PAIDI 2020); [Sponsor 2] PID2020-119073GB-I00 (Speech-AEPs), Ministry of Science and Innovation, Government of Spain
  Status: undergoing
• Phd candidate: Nicolas Müller Locatelli
  Title: Registro de potenciales evocados auditivos multi-nivel de alta resolución en intensidad. Aplicaciones clínicas
  Supervisors: Ángel de la Torre Vega y José Luis Vargas Fernández
  Department: Programa de Doctorado en Medicina y Salud Pública, University of Granada
  Sponsorship: [Sponsor 1] P21.00152 (E-HHL-D), Andalusian Plan for Research, Development, and Innovation (PAIDI 2020); [Sponsor 2] PID2020-119073GB-I00 (Speech-AEPs), Ministry of Science and Innovation, Government of Spain
  Status: undergoing
• Phd candidate: Marta Martínez Martínez
  Title: New strategies for recording auditory evoked potentials using randomized monaural intensity stimulation and binaural stimulation <<Nuevas estrategias de registro de potenciales evocados auditivos utilizando estimulación monoaural aleatorizada en intensidad y estimulación binaural>>
  Supervisors: Isaac M. Álvarez, Joaquín T. Valderrama
  Department: Programa de Doctorado en Medicina y Salud Pública, University of Granada
  Date of the Award: 12/12/2022
  Grade: Cum Laude
  Sponsorship: [Sponsor 1] B-TIC-382-UGR20, Andalusian Operative Program FEDER 2014-2020. [Sponsor 2] PID2020-119073GB-I00, Ministry of Science and Innovation, Government of Spain
  PhD thesis: Download

Science dissemination

• [November 2025] Science outreach event – Live auditory evoked potential recording
  Title: Adquisición de biopotenciales: ¿Cómo estás corazón? (biopotenciales cardíacos) – Podemos ver lo que oyes (potenciales evocados auditivos) //
  Acquisition of biopotentials: How are you, heart? (cardiac biopotentials) – we can see what you hear (auditory evoked potentials)
  Program: Semana de la Ciencia 2025 // 2025 Science Week
  Performers: Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz, Buğçe Özer
  Target audience: Secondary education students
  Where: School of Technology and Telecommunications Engineering (https://etsiit.ugr.es/), University of Granada, Spain
  More info: photo, slides, link
• [September 2025] Science outreach event – Live auditory evoked potential recording
  Title: Adquisición de biopotenciales: ¿Cómo estás corazón? (biopotenciales cardíacos) – Podemos ver lo que oyes (potenciales evocados auditivos) //
  Acquisition of biopotentials: How are you, heart? (cardiac biopotentials) – we can see what you hear (auditory evoked potentials)
  Program: La noche europea de los investigadores 2025 // 2025 European Researchers’ Night
  Performers: Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz, Juan Antonio Torres Lara
  Target audience: Activity for educational centers
  Where: Paseo del Salón, Granada city center
  More info: photo, slides, link
• [July 2025] Science outreach event – Live auditory evoked potential recording
  Title: Mi cuerpo eléctrico: Taller de biopotenciales cardiacos y potenciales evocados auditivos // My electric body: Workshop on cardiac biopotentials and auditory evoked potentials
  Program: Verano con Ciencia 2025 // Summer with Science 2025
  Performers: Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz, Juan Antonio Torres Lara
  Target audience: Primary education students
  Where: Science Park, Andalusia, Granada
  More info: photo, slides, detailed workshop description, press release 1, press_release_2, activity program
• [June 2025] Science outreach event – Live auditory evoked potential recording
  Title: Mi cuerpo eléctrico: Taller de biopotenciales cardiacos y potenciales evocados auditivos // My electric body: Workshop on cardiac biopotentials and auditory evoked potentials
  Program: Workshop in a Science Park
  Performers: María Raya, Andrea Sanz, Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz
  Target audience: Secondary education students
  Where: Science Park, Andalusia, Granada
  More info: photo, slides
• [May 2025] Science outreach event – Live auditory evoked potential recording
  Title: Taller sobre biopotenciales cardíacos y potenciales evocados auditivos // Workshop on cardiac biopotentials and on auditory evoked potentials
  Program: Workshop for future engineers
  Performers: Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz
  Target audience: Engineering students
  Where: School of Technology and Telecommunications Engineering, University of Granada, Spain
  More info: photo, slides
• [April 2025] Science outreach event – Live auditory evoked potential recording
  Title: ¿Cómo estás, corazón? Taller de biopotenciales cardiacos // How are you, my heart? Workshop on cardiac biopotentials
  Program: Feria de las Ingenierías // Engineering Fair
  Performers: María Raya, Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz
  Target audience: Secondary and High School students
  Where: School of Technology and Telecommunications Engineering (https://etsiit.ugr.es/), University of Granada, Spain
  More info: photo, slides, link
• [January 2023 – May 2023]: Project oriented to educate high school students on research methods
  Title: Investigando la percepción binaural // Investigating binaural hearing
  Program: Project for initiating Andalusian secondary students on research methods and innovation (PIIISA)
  Participants: Ángel de la Torre Vega, Isaac Manuel Álvarez Ruiz, Joaquín Tomás Valderrama Valenzuela, José Carlos Segura Luna + 37 students from 4 high schools + 1 teacher per school
  Target audience: Secondary education students
  Where: School of Technology and Telecommunications Engineering (https://etsiit.ugr.es/), University of Granada, Spain
  More info: poster, oral presentation, project summary, audio examples and additional material related to binaural perception