PhD successfully defended by Valentina Zapata Rodriguez

Friday 29 May 20

The PhD thesis submitted by Valentina Zapata Rodriguez presents an original set of four coherent studies related to practical issues involved with measuring auditory steady state responses (ASSR) in clinical environments. ASSRs are evoked auditory potentials elicited in response to repeated transient stimuli or modulated tones and are ideal for early diagnostic screening and intervention methods for pre-lingual infants and hard-to-test adults with hearing loss. In this technique, an acoustic stimulus is presented via a loudspeaker near the listener's ear in an audiometric test room. While previous work has demonstrated that ASSRs may be well suited for evaluating hearing aid fitting, these studies have typically been conducted in acoustically controlled lab environments. Since room reverberation reduces amplitude modulation and ASSRs are dependent on the amplitude modulations in the acoustic signal received by the ear, the acoustic properties of the clinical test room could significantly  influence ASSR results.

Valentina Zapata Rodriguez's work is a valuable step forward in characterizing the relationship between room acoustics and ASSRs and the examining committee agreed that Valentinas doctoral thesis is a valuable work in the field of hearing impairment assessment and hearing aid fitting for patients who cannot reveal a voluntary  response. Through the well-organized document, it is demonstrated that the reverberation of the typical audiometric test rooms reduces the level of ASSR, as well as its detection rate, and extends the testing time. This work highlights the need for the development of acoustic standards for rooms suitable for ASSR testing and identifies physical measures that are well suited for this purpose.

The examiners further agreed that the thesis is of high scientific quality and meets the standard for a PhD degree.

Congratulations to Valentina on her achievement.