Individual Monitoring of Vocal Effort With Relative Fundamental Frequency: Relationships With Aerodynamics and Listener Perception

Abstract

Purpose The acoustic measure Relative Fundamental Frequency (RFF) was investigated as a potential objective measure to track variations in vocal effort within and across individuals. Methods Twelve speakers with healthy voices created purposeful modulations in their vocal effort during speech tasks. RFF and an aerodynamic measure of vocal effort, the ratio of sound pressure level to subglottal pressure level, were estimated from the aerodynamic and acoustic signals. Twelve listeners also judged the speech samples for vocal effort using the visual sort and rate method. Results Relationships between RFF and both the aerodynamic and perceptual measures of vocal effort were weak across speakers (R2 = 0.06–0.26). Within speakers, relationships were variable, but much stronger on average (R2 = 0.45–0.56). Conclusions RFF showed stronger relationships between both the aerodynamic and perceptual measures of vocal effort when examined within individuals relative to across individuals. Future work is necessary to establish these relationships in individuals with voice disorders across the therapeutic process.

The Relationship Between Relative Fundamental Frequency and a Kinematic Estimate of Laryngeal Stiffness in Healthy Adults

“…RFF onset cycle 1 ranged from −1.45 to 3.26 ST across all tasks. The typical speaking voice task produced an onset cycle 1 average of 1.83 ST (SD = 0.98, range = −0.32 to 3.03 ST), which is also within the typical range reported in recent studies with healthy individuals (Lien, 2015;Lien et al, 2015).…”

“…Multiple factors are thought to contribute to RFF values, including laryngeal muscle tension, vocal fold abductory movement, and aerodynamic forces (Lien, Michener, Eadie, & Stepp, 2015;Stepp, Hillman, & Heaton, 2010b). Laryngeal tension, in particular, is hypothesized to influence RFF values for both offset and onset.…”

“…A relationship between RFF and the modulation of vocal effort has also been reported. Lien et al (2015) examined RFF in healthy speakers across five speaker-modulated levels of effort: relaxed, normal, slightly strained, moderately strained, and maximally strained. Findings reported no Figure 1.…”

“…In the same study, RFF offset cycle 10 had a moderately strong ability to accurately and specifically predict vocal hyperfunction in comparison with controls, whereas the prediction by RFF onset cycle 1 was closer to chance. However, RFF onset cycle 1 has been shown to significantly correlate with listener perceptions of vocal effort in individuals with spasmodic dysphonia and in healthy speakers who modulated their vocal effort (Eadie & Stepp, 2013;Lien et al, 2015). Therefore, although RFF onset cycle 1 may be more specific to listener perception of vocal tension, it is possible that RFF offset cycle 10 may be more sensitive to the small changes in tension that are not yet detected by a naïve listener (Eadie et al, 2010;Kelchner et al, 2010).…”

Analysis of Deaf Speakers’ Speech Signal for Understanding the Acoustic Characteristics by Territory Specific Utterances

“…The progress in the sophisticated processing and analyzing techniques in speech science, electrical engineering and computer science have facilitated to understand the speech production process [13]. These technological growths helped to examine the deaf speakers' speech signal as well as to develop clinical assessment and training procedures [14] [15].…”