Proceedings Fonetik 2009 - Institutionen för lingvistik

More documents

Recommendations

Info

Proceedings, FONETIK 2009, Dept. of Linguistics, Stockholm UniversityAs absence of vocal fold contact produces agreat reduction of the EGG signal amplitude,such amplitude reductions were easy to identifyin the recording. The subglottal pressures appearingimmediately before and after a suddenamplitude drop were assumed to lie just aboveand just below the CTP, respectively, so theaverage of these two pressures was accepted asthe CTP. For each subject, CTP was determinedin at least three sequences for each pitchand the average of these estimates was calculated.The same method was applied for determiningthe PTP.ResultsBoth thresholds tended to increase with F0, asexpected, and both were mostly higher after theloading. Figure 3 shows PTP and CTP beforeand after vocal loading for one of the untrainedmale subjects. The variation with F0 was lessevident and less systematic for some subjects.Table 1 lists the mean and SD across F0 of theafter-to-before ratio for the subjects. The F0range produced by the subjects was slightlynarrower than one and a half octave for themale subjects and two octaves for the trainedfemale but only 8 semitones for the untrainedfemale. The after-to-before ratio for CTP variedbetween 1.32 and 1.06 for the male subjects.The corresponding variation for PTP was 1.74and 0.98. The means across subjects were similarfor CTP and PTP. Vocal loading caused astatistically significant increase of both CTPand PTP (paired samples t-test, p
Proceedings, FONETIK 2009, Dept. of Linguistics, Stockholm Universityrather good approximations of the average CTPbefore and after warm-up. However, the untrainedsubjects in the present experimentshowed an irregular variation with F0, so approximatingtheir CTP curves with modifiedversions of Titze’s equation seemed pointless.A limitation of the CTP is that, obviously, itcannot be measured when the vocal folds fail tocollide. This often happens in some dysphonicvoices in the upper part of the female voicerange, and in male falsetto phonation.The main finding of the present investigationwas that CTP increased significantly after vocalloading. For the two trained subjects, the effectwas minimal, and these subjects did not experienceany vocal fatigue after the vocal loading.On average, the increase was similar for CTPand PTP. This supports the assumption thatCTP reflects similar vocal fold characteristicsas the PTP.Our results suggest that the CTP may be usedas a valuable alternative or complementation tothe PTP, particularly in cases where it is difficultto determine the PTP accurately.ConclusionsThe CTP seems a promising alternative or complementto the PTP. The task of phonating atphonation threshold pressure seems more difficultfor subjects than the task of phonating atthe collision threshold. The information representedby the CTP would correspond to thatrepresented by the PTP. In the future, it wouldbe worthwhile to test CTP in other applications,e.g., in a clinical setting with patients beforeand after therapy.ReferencesChang A. and Karnell M.P. (2004) PerceivedPhonatory Effort and Phonation ThresholdPressure Across a Prolonged Voice LoadingTask: A Study of Vocal Fatigue. J Voice 18,454-66.Cleveland T. and Sundberg J. (1985) Acousticanalyses of three male voices of differentquality. In A Askenfelt, S Felicetti, E Jansson,J Sundberg, editors. SMAC 83. Proceedingsof the Stockholm Internat MusicAcoustics Conf, Vol. 1 Stockholm: Roy SwAcad Music, Publ. No. 46:1, 143-56.Enflo L. and Sundberg J. (forthcoming) VocalFold Collision Threshold Pressure: An Alternativeto Phonation Threshold Pressure?Ladefoged P. and McKinney NP. (1963) Loudness,sound pressure, and subglottal pressurein speech. J Acoust Soc Am 35, 454-60.Milbrath R.L. and Solomon N.P. (2003) DoVocal Warm-Up Exercises Alleviate VocalFatigue?, J Speech Hear Res 46, 422-36.Solomon N.P. and DiMattia M.S. (2000) Effectsof a Vocally Fatiguing Task and SystematicHydration on Phonation ThresholdPressure. J Voice 14, 341-62.Titze I. (1992) Phonation threshold pressure: Amissing link in glottal aerodynamics. JAcoust Soc Am 91, 2926-35.Verdolini-Marston K., Titze I. and Druker D.G.(1990) Changes in phonation threshold pressurewith induced conditions of hydration. JVoice 4, 142-51.AcknowledgementsThe kind cooperation of the subjects is gratefullyacknowledged. This is an abbreviatedversion of a paper which has been submitted tothe Interspeech conference in Brighton, September2009.27
Page 1 and 2: Department of LinguisticsProceeding
Page 3 and 4: Proceedings, FONETIK 2009, Dept. of
Page 25: Proceedings, FONETIK 2009, Dept. of
Page 41 and 42: Proceedings, FOETIK 2009, Dept. of
Page 77 and 78:
Proceedings, FONETIK 2009, Dept. of
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Proceedings, FOETIK 2009, Dept. of
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227:
Department of LinguisticsPhonetics
show all

Proceedings Fonetik 2009 - Institutionen för lingvistik

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?