Horizontal directivity of low- and high-frequency energy in speech and singing

In this paper, a multimodal theory accounting for higher order acoustical propagation modes is presented as an extension to the classical plane wave theory. This theoretical development is validated against experiments on vocal tract replicas, obtained using a 3D printer and finite element simulations. Simplified vocal tract geometries of increasing complexity are used to investigate the influence of some geometrical parameters on the acoustical properties of the vocal tract. It is shown that the higher order modes can produce additional resonances and anti-resonances and can also strongly affect the radiated sound. These effects appear to be dependent on the eccentricity and the cross-sectional shape of the geometries. Finally, the comparison between the simulations and the experiments points out the importance of taking visco-thermal losses into account to increase the accuracy of the resonance bandwidths prediction.

Section: Discussionmentioning

confidence: 97%

Effects of higher order propagation modes in vocal tract like geometries

Blandin

Arnela

Laboissière

et al. 2015

“…Moore et al (2008) attributes these higher band levels to noise from the microphone used in the earlier study, but it is possible that microphone placement or the recording material itself caused the differences in HFE, leading to these disparities (e.g., an increase in the number of voiceless fricatives would potentially lead to increased HFE band levels in the LTAS). The SPLs reported here were verified by multiple Type 1 precision microphones recording simultaneously in the anechoic chamber (Monson et al, 2012).…”

Section: Resultsmentioning

confidence: 99%

“…(A distance of 60 cm was used here due to space constraints in the anechoic chamber; see Monson et al, 2012) True mean levels reported here were calculated by converting dB levels to linear squared-pressure amplitudes, taking the mean, and converting this value back to dB. None of the signals were "pre-emphasized" in this study, thus the levels reported represent actual HFE levels of the raw singing/speech signal.…”

Section: Acoustical Analysismentioning

confidence: 99%

Analysis of high-frequency energy in long-term average spectra of singing, speech, and voiceless fricatives

Monson

Lotto

Story

2012

Self Cite

The human singing and speech spectrum includes energy above 5 kHz. To begin an in-depth exploration of this high-frequency energy (HFE), a database of anechoic high-fidelity recordings of singers and talkers was created and analyzed. Third-octave band analysis from the long-term average spectra showed that production level (soft vs normal vs loud), production mode (singing vs speech), and phoneme (for voiceless fricatives) all significantly affected HFE characteristics. Specifically, increased production level caused an increase in absolute HFE level, but a decrease in relative HFE level. Singing exhibited higher levels of HFE than speech in the soft and normal conditions, but not in the loud condition. Third-octave band levels distinguished phoneme class of voiceless fricatives. Female HFE levels were significantly greater than male levels only above 11 kHz. This information is pertinent to various areas of acoustics, including vocal tract modeling, voice synthesis, augmentative hearing technology (hearing aids and cochlear implants), and training/therapy for singing and speech.

“…However, average performance on stop consonant categorization (50.6%) was nearly as good as average accuracy for the fricatives (59.7%). One might also predict greater performance using HFE for female speech given that female speech tends to have greater HFE overall (Monson et al, 2012a). Whereas accuracy was greater for female-produced tokens, these differences were relatively modest (3 percentage points for vowels and 4 percentage points for consonants).…”

Section: Discussionmentioning

confidence: 99%

“…The purpose of the low-frequency masker was to ensure that listeners were using HFE, per se, and not distortion products that may be present in the lower frequencies. The HFE amplitude was set to 47 dB root-mean-square sound pressure level (SPL rms ) and the low-frequency masker was set to 62 dB SPL rms , which are typical levels produced during normal speech for a speaker facing the listener (Monson et al, 2012a(Monson et al, , 2012b.…”

Section: Stimulimentioning

confidence: 99%

Phoneme categorization relying solely on high-frequency energy

Vitela

Monson

Lotto

2014

Self Cite

Speech perception studies generally focus on the acoustic information present in the frequency regions below 6 kHz. Recent evidence suggests that there is perceptually relevant information in the higher frequencies, including information affecting speech intelligibility. This experiment examined whether listeners are able to accurately identify a subset of vowels and consonants in CV-context when only high-frequency (above 5 kHz) acoustic information is available (through high-pass filtering and masking of lower frequency energy). The findings reveal that listeners are capable of extracting information from these higher frequency regions to accurately identify certain consonants and vowels.