Date of Award
Master of Science
Communication Sciences and Disorders
Marylou P. Gelfer
James A. Bashford, Carol H. Seery
A review of recent literature suggested that cepstral- and spectral-based acoustic measures showed good potential as objective measures of dysphonia for clinical application. However, the small numbers of normal subjects in previous research and wide age ranges prevent a good estimation of the performance of normal speakers of various ages on these measures. Therefore, the purpose of this study was to provide normative data for Long-Term Average spectral- and cepstral-based measures for both men and women in two different age groups to aid clinicians with assessing and treating voice disorders. Sixty participants consisting of fifteen males and fifteen females, ages 20-30 years, and fifteen males and fifteen females, ages 40-50 years contributed speech samples to be analyzed in this study. Speakers were asked to sustain the vowels /a/ and /i/, read out loud four CAPE-V stimulus sentences, and the 2nd and 3rd sentence of the Rainbow Passage. Dependent variables were Cepstral Peak Prominence (CPP), Low-to-High Spectral Ratio (L/H spectral ratio), and Cepstral Peak Prominence Fundamental Frequency (CPP F0) for both vowels and connected speech. Male voice quality (CPP and L/H spectral ratio) was better in vowels /a/ and /i/, but female voice quality was better (CPP values) for connected speech. Age did not affect voice quality for vowels /a/ and /i/; however, it did affect it for connected speech. Younger speakers had better voice quality (CPP) than older speakers. In general, for both vowels and connected speech, younger women had markedly higher CPP F0 values than older women, while older men had slightly higher CPP F0 values compared to younger men. It was concluded that separate normative data should be applied clinically for all four age/gender groups. The maximum limit of the ADSV extraction range for male participants should be changed from 300 Hz to 200 Hz for connected speech readings to obtain accurate CPP F0 measures. Furthermore, due to limited research, data should be analyzed both with and without vocalic detection until it becomes clear which one is more valid. Further research is recommended to improve both the procedures and reference data available for voice quality.
Garrett, Rachel, "Cepstral- and Spectral-Based Acoustic Measures of Normal Voices" (2013). Theses and Dissertations. 217.