The effect of change in spectral slope and formant frequencies on the perception of loudness

Sirisha Duvvuru, Molly Erickson
Journal of Voice 2013, 27 (6): 691-7

OBJECTIVE/HYPOTHESIS: This study attempts to understand how changes in spectral slope and formant frequency influence changes in perceived loudness. It was hypothesized that voices synthesized with steeper spectral slopes will be perceived as less loud than voices synthesized with less steep spectral slopes, in spite of the fact that they are of equal root mean square (RMS) amplitude. It was also hypothesized that stimuli with higher formant patterns will be perceived as louder than those with lower formant patterns, in spite of the fact that they are of equal RMS amplitude.

STUDY DESIGN: Repeated measures factorial design.

METHODS: For the pitches A3, C4, B4, and F5, three different source signals were synthesized with varying slopes of -9, -12, and -15 dB/octave using a frequency vibrato rate of 5.6 Hz and a frequency vibrato extent of 50 cents. Each of the three source signals were filtered using two formant patterns, a lower formant pattern typical of a mezzo-soprano (pattern A) and a higher formant pattern typical of a soprano (pattern B) for the vowel /a/. For each pitch, the six stimuli were combined into all possible pairs and normalized to equal RMS amplitude. Listeners were presented with 120 paired stimuli (60 pairs repeated twice). The listener's task was to indicate whether the first or second stimulus in the pair was louder.

RESULTS: Generally, as the spectral slope decreased, perceived loudness increased, with the magnitude of the perceived difference in loudness being related to the degree of difference in spectral slope. Likewise, at all pitches except A3, perceived loudness increased as formant frequency increased.

CONCLUSION: RMS amplitude is an important predictor of loudness perception, but many other factors also affect the perception of this important vocal parameter. Spectral composition is one such factor and must be considered when using loudness perception in the process of clinical diagnostics.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"