Relevant Thesis-Based Degree Programs
Affiliations to Research Centres, Institutes & Clusters
Auditory scene analysis; perception and production of disordered speech
Complete these steps before you reach out to a faculty member!
- Familiarize yourself with program requirements. You want to learn as much as possible from the information available to you before you reach out to a faculty member. Be sure to visit the graduate degree program listing and program-specific websites.
- Check whether the program requires you to seek commitment from a supervisor prior to submitting an application. For some programs this is an essential step while others match successful applicants with faculty members within the first year of study. This is either indicated in the program profile under "Admission Information & Requirements" - "Prepare Application" - "Supervision" or on the program website.
- Identify specific faculty members who are conducting research in your specific area of interest.
- Establish that your research interests align with the faculty member’s research interests.
- Read up on the faculty members in the program and the research being conducted in the department.
- Familiarize yourself with their work, read their recent publications and past theses/dissertations that they supervised. Be certain that their research is indeed what you are hoping to study.
- Compose an error-free and grammatically correct email addressed to your specifically targeted faculty member, and remember to use their correct titles.
- Do not send non-specific, mass emails to everyone in the department hoping for a match.
- Address the faculty members by name. Your contact should be genuine rather than generic.
- Include a brief outline of your academic background, why you are interested in working with the faculty member, and what experience you could bring to the department. The supervision enquiry form guides you with targeted questions. Ensure to craft compelling answers to these questions.
- Highlight your achievements and why you are a top student. Faculty members receive dozens of requests from prospective students and you may have less than 30 seconds to pique someone’s interest.
- Demonstrate that you are familiar with their research:
- Convey the specific ways you are a good fit for the program.
- Convey the specific ways the program/lab/faculty member is a good fit for the research you are interested in/already conducting.
- Be enthusiastic, but don’t overdo it.
G+PS regularly provides virtual sessions that focus on admission requirements and procedures and tips how to improve your application.
ADVICE AND INSIGHTS FROM UBC FACULTY ON REACHING OUT TO SUPERVISORS
These videos contain some general advice from faculty across UBC on finding and reaching out to a potential thesis supervisor.
Graduate Student Supervision
Doctoral Student Supervision
Dissertations completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest dissertations.
Breathiness is a perceptual characteristic of voice that is associated with the presence of aspiration noise in the speech signal. Previous studies investigated how changes in the noise-to- harmonics ratio (NHR) and in the slope of the glottal spectrum affected noise discrimination. However, the effects of spectral properties (such as formant frequencies and fundamental frequency, fo) on breathiness have remained largely unexplored. The first study of this thesis (Chapter 2) investigated noise discrimination in synthesized vowels as a function of vowel spectrum (/æ/ and /i/ for different speakers) while the amount of aspiration noise and the glottal spectrum’s slope was fixed. The fo was allowed to covary. Findings indicated that both vowel spectrum and fo affected noise discrimination. Additional studies of this thesis investigated noise perception using harmonic series (maskers) with equal-amplitude components so that the effects of spectral factors could be manipulated. The effect of masker level and fo on noise perception was investigated using band-limited maskers in three non-overlapping frequency bands. These bands were set such that listeners predominantly relied on spectral cues (resolved frequency components), temporal cues (unresolved components), or a combination of both (resolved and unresolved components). Experiments with wideband maskers were also performed. The effects of frequency band, level and fo were investigated using noise detection Chapter 3 and noise discrimination tasks (Chapter 4 and Chapter 5). The results showed that fo affected noise detection and discrimination in bands that contained spectral cues, but not temporal cues. Masker level had a large effect on the detection thresholds when temporal cues were used, but the effect of masker level on discrimination thresholds were inconclusive. Detection thresholds for different frequency bands depended on fo and masker level, but discrimination performance was consistently poor in the highest frequency band where temporal cues were used for a given NHR. In conclusion, the effect of fo on noise cues depended on the auditory processing mechanism (spectral vs temporal), and whether the noise was near threshold or suprathreshold. Level differences had a co-modulating effect on the results that were explained by way of the non- linear amplification of the basilar membrane.
Master's Student Supervision
Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.
Objective: Recent studies in rodents show that noise exposure may cause permanent damage to inner hair cell synapses, even when hearing thresholds return to their baseline (Fernandez et al., 2015; Liberman et al., 2015). Emerging evidence indicates that similar damage may occur in humans (Liberman et al., 2016), and is known in the literature as cochlear synaptopathy (CS) or hidden hearing loss. CS would likely cause functional deficits in temporal coding and speech-in-noise (Furman, Kujawa & Liberman, 2013; Kumar et al., 2012). The objective of the current research was to compare the speech-in-noise performance of an at-risk group of student musicians to a control group of individuals with limited noise exposure. Method: The experimental group consisted of 20 student musicians (MAGE = 22.7, SD = 3, range =18-28). The control group was comprised of 22 students with normal hearing and limited noise exposure (MAGE = 21.9, SD = 2.5, range =18-27). Previous noise exposure was estimated using the Noise Exposure Structured Interview (NESI; Guest et al., 2018). The hearing-in-noise test (HINT; Nillson et al., 1994) and the random gap-in-noise test (RGDT; Keith, 2000) were administered to assess temporal and speech-in-noise perception abilities. A Bayesian multilevel linear model was used to investigate differences in HINT scores between groups and conditions. Results: The musician group showed higher estimated lifetime exposure than the control group. Differences were found between conditions of the HINT, but not between groups. No association was found between HINT-ITD and estimated lifetime noise exposure. Discussion: It is possible that the population studied did not have sufficient noise exposure to exhibit difficulties processing temporal stimuli. Given the current literature on CS in humans, strict inclusion criteria, broad research protocols and interdisciplinary collaborations are warranted. Future studies should focus on finding behavioral tests with good sensitivity and specificity to reliably diagnose CS in humans in older musicians.
Cochlear implants are generally considered the most successful of all sensory neural prostheses currently in use (Wilson and Dorman, 2008). Investigation of auditory perception with cochlear implants is important for developing effective and evidence-based approaches for intervention and management of profound hearing loss. Various phenomena of auditory perception have begun to be explored with cochlear implant users. However, perception of a phenomenon that allows listeners to perceptually restore the continuity of sounds that are partially masked or interrupted by other sounds (“auditory induction” or “auditory continuity”) has not yet been investigated in a group of listeners with cochlear implants. In the current study a group of 10 listeners with cochlear implants and 10 control listeners with normal-hearing provided judgments on the continuity of a pure tone signal in the presence of four levels of a narrow-band noise masker. The group of listeners with cochlear implants reported perception of auditory continuity, but did so for lower levels of the masker when compared to the normal-hearing control group. A secondary experiment investigated simultaneous masking in listeners with cochlear implants using the same masker levels used in the continuity experiment. The cochlear implant group displayed effective masking at a lower level than the normal-hearing control group, the same level at which auditory continuity was perceived in the first experiment. The differences observed between the two groups may be attributable to the greater effects of masking resulting from poorer frequency resolution, lack of temporal fine structure information and reduced dynamic range for users of cochlear implants compared with listeners with normal-hearing.
This study was designed to explore the effects of topic title and simulated high frequency hearing loss on language comprehension by normal, healthy adults. Thirty-two adult participants with no history of cognitive deficits participated in this study. Each participant listened to four different passages in four different conditions. The four conditions were: (1) title with normal hearing, (2) title with simulated high frequency hearing loss, (3) no title with normal hearing and (4) no title with simulated high frequency hearing loss. Passages were presented segment-by-segment using the auditory moving window technique; most segments were short sentences or clauses. Participants listened to each segment at their own pace by pressing a key. Pause times between segments and overall listening time were recorded for each passage. After listening to each passage, participants were asked to recall out loud what they understood and remembered from the passage. Recall was transcribed and percentages of recalled propositions were calculated. In order to observe changes in processing across a passage, mean pause duration values were also compared across passage position (beginning, middle and end of a passage). The results showed that topic titles facilitated listening comprehension, as shown through better recall performance and reduced processing time. The knowledge of topic titles also reduced the time required for processing information at the beginning of the passage, showing that the knowledge of topic titles facilitates the building of mental representations. The simulated high frequency hearing loss condition did not prove to consistently tax working memory resources during language comprehension. The findings also provided evidence about the relationship between working memory ability and recall performance. Overall, these findings are consistent with the predictions of current language comprehension models.