Detection of high-frequency energy changes in sustained vowels produced by singers

Abstract

The human voice spectrum above 5 kHz receives little attention. However, there are reasons to believe that this high-frequency energy (HFE) may play a role in perceived quality of voice in singing and speech. To fulfill this role, differences in HFE must first be detectable. To determine human ability to detect differences in HFE, the levels of the 8-and 16-kHz center-frequency octave bands were individually attenuated in sustained vowel sounds produced by singers and presented to listeners. Relatively small changes in HFE were in fact detectable, suggesting that this frequency range potentially contributes to the perception of especially the singing voice. Detection ability was greater in the 8-kHz octave than in the 16-kHz octave and varied with band energy level.

Detection of high-frequency energy level changes in speech and singing

“…The draw has been due to sparse but increasingly conclusive evidence that high-frequency energy (HFE, defined here as the energy in the 8-and 16-kHz octave bands or 5.7-22 kHz) plays a larger perceptual role in speech perception than previously assumed. The percepts impacted by HFE that have been reported thus far are speech and voice quality (Olson, 1947;Moore and Tan, 2003;Moore et al, 2010;Monson et al, 2011), speech source localization (Best et al, 2005), speech intelligibility (Lippmann, 1996;Stelmachowicz et al, 2001;Apoux and Bacon, 2004;Moore et al, 2010), and child word-learning (Stelmachowicz et al, 2007;Pittman, 2008). Some studies indicate that HFE could also play a role in the perception of voice disorders (de Krom, 1995;Hartl et al, 2003) and in talker identification (Hayakawa and Itakura, 1995;White, 2001;Liss et al, 2010).…”

“…First, the major contributors to HFE in running speech are consonants (Monson et al, 2011), and particularly voiceless fricatives (Jongman et al, 2000;Maniwa et al, 2009;Monson et al, 2012). Second, it has been suggested that HFE is of greater perceptual consequence for female talkers (Stelmachowicz et al, 2001), who tend to have higher HFE levels, at least in the 16-kHz octave (Monson et al, 2012).…”

“…Thus some studies that have reported strong perceptual effects of HFE used only female speech (Lippmann, 1996;Stelmachowicz et al, 2007;Pittman, 2008). Finally, in the past, HFE has largely been associated with sound quality (e.g., Moore and Tan, 2003;Monson et al, 2011), suggesting the primary perceptual effect of HFE changes is a change in sound quality. Because sound quality is of primary concern in singing voice production, further examination of the role of HFE in singing voice (i.e., beyond isolated vowels) is warranted.…”

“…A previous study by Monson et al (2011) showed that human listeners could detect small changes in HFE level in isolated vowels produced by two male singers of differing vocal timbre. That study consisted of listeners participating in a perceptual discrimination task using 500-ms excerpts of sustained /a/ vowels produced by the singers as stimuli with the 8-and 16-kHz center-frequency octave bands individually and incrementally attenuated.…”

“…Because Monson et al (2011) used brief isolated voice samples from men, the generalization of this study to male and female running speech and singing is uncertain. First, the major contributors to HFE in running speech are consonants (Monson et al, 2011), and particularly voiceless fricatives (Jongman et al, 2000;Maniwa et al, 2009;Monson et al, 2012).…”