Research Projects

The SHS-Lab currently hosts the following funded research projects:

• Austrian Science Fund (FWF KLI722-B30): 2018 – 2024
  • Program clinical research: “Objective differentiation of dysphonic voice quality types”
  • PI: Philipp Aichinger

PR-abstract:

Voice problems are not completely understood yet, partly because conventional methods for clinical examination are limited. Aim of this research project is to create computerized methods which automatically recognize and identify reliably voice problems in microphone recordings of patients’ voices.

Videos of the throat and microphone recordings of 230 patients with voice problems are obtained. Super slow motion videos with 4000 images per second are used, because the vocal folds, which are located in the larynx, normally vibrate very fast during voice production, more often than 100 times per second. To visualize irregularities, videos showing two seconds of vocal fold vibration are slowed down to a playing time of five minutes.

The researchers investigate how the vocal fold vibration relates to the sound of the voice. In particular, three voice types are payed attention to. First, a so called “vocal fry” is a very low pitched type of voice. This voice type may be evocative of the “Strohbass” singing register. Sometimes, it is possible to hear individual pulses of the vocal folds in these voices. Second, extrapulsed voices are investigated. These may be compared to a common phenomenon in human heart beating, i.e., extra systoles. Just as a human heart may sometimes stumble every now and then, extra pulses may occur in the voice. Frequently occurring extra pulses may be a sign of a voice problem, may be perceived to sound “raspy”. Third, phase differences between the left and the right vocal fold may occur in voice disorders. To understanding phase differences, one could try to bounce two basketballs with the left and the right hand simultaneously, and notice that the balls will hardly ever hit the ground at exactly same time, and two separate bouncing sounds will be audible every time the balls hit the ground. Such timing differences also occur in vocal folds, and are a sign of a voice problem. Interestingly, instead of hearing the two vocal folds separately, listeners have reported to hear a certain type of “rumbling” in voices with phase differences. This is mainly because the frequency of the vocal folds is much higher than the frequency of basketballs.

A diverse approach is chosen to investigate how the vocal folds vibrate, and how abnormal voices sound to listeners. The project comprises computer-based science, patient data, and auditory experiments. The results may be applied for improving clinical voice quality assessment.

JOURNAL Publications linked with FWF KLI722-B30:

• Aichinger, P., & Pernkopf, F. (2021). Synthesis and Analysis-by-Synthesis of Modulated Diplophonic Glottal Area Waveforms. IEEE/ACM Transactions on Audio Speech and Language Processing, 29, 914–926. https://doi.org/10.1109/TASLP.2021.3053387

• Devaraj, V., & Aichinger, P. (2021). Modelling of Amplitude Modulated Vocal Fry Glottal Area Waveforms Using an Analysis‐by‐Synthesis Approach. Applied Sciences (Switzerland), 11(5), 1990. https://doi.org/10.3390/app11051990

• Bulusu, S., Kumar, S., Švec, J., & Aichinger, P. (2021). Fitting synthetic to clinical kymographic images for deriving kinematic vocal fold parameters: Application to left-right vibratory phase differences. Biomedical Signal Processing and Control, 63. https://doi.org/10.1016/j.bspc.2020.102253

• Drioli, C., & Aichinger, P. (2021). Modelling sagittal and vertical phase differences in a lumped and distributed elements vocal fold model. Biomedical Signal Processing and Control, 64, 102309. https://doi.org/10.1016/j.bspc.2020.102309

• Aichinger, P., Pernkopf, F., & Schoentgen, J. (2019). Detection of extra pulses in synthesized glottal area waveforms of dysphonic voices. Biomedical Signal Processing and Control, 50, 158–167. https://doi.org/10.1016/j.bspc.2019.01.007