Speech Acoustics1 Clinical Application of Frequency and Intensity Variables Frequency Variables Amplitude and Intensity Variables Voice Disorders Neurological Disorders

Speech Acoustics2 Frequency Variables Average Fo. Fo frequency Variability Maximum Phonational Frequency Range

Speech Acoustics3 Frequency Variables continued Average Fundamental Frequency –Variables Age and Gender –Infants (350 to 500 Hz) –Ages 3 through 10 (270 to 300 Hz) –Adults »Males (120 Hz) »Females (220 Hz) Individual differences

Speech Acoustics4 Frequency Variables continued Frequency Variability –Normal SD is plus/minus 20 to 35 dB –Variables that affect variablity Emotions Fatigue Different grammatical constructions Individual differences Age (decreases through lifetime) Neuromuscular or other disorders –Frequency variability can be used as a baseline when examining different voice disorders

Speech Acoustics5 Frequency Variables continued Maximum Phonational Frequency Range (MPFR) Differs from Fo which refers to connected speech. MPFR is the range of frequency that you can produce (provide example).

Speech Acoustics6 Frequency Variables continued Mean MPFR is around 2.5 octaves or 30 semitones. Not a great deal of variability for age and gender. Trained singers have higher MPFR. Poor physical condition regardless of age may signal a problem with the speaker.

Speech Acoustics7 Amplitude and Intensity Variables Average Amplitude Level Amplitude Variability Dynamic Range Voice Range Profile

Speech Acoustics8 AmplitudeVariables continued Average Amplitude Level –Refers to normal conversational levels –Usually around 65 to 80 dB SPL (or 45 to 60 dB HL) –No major age or gender effects. –May increase in background noise (Lombard effect) –Lower amplitude may be a result of a pathology.

Speech Acoustics9 AmplitudeVariables continued Amplitude Variability –Changes in amplitude due to … Speaker’s mood and feeling Message such as stress, duration, syllabic structure, etc. –SD is around 10 dB, but varies depending upon level of excitement. –Lack of amplitude variation = monotone, and may be difficult to understand.

Speech Acoustics10 AmplitudeVariables continued Dynamic Range –Intensity difference between soft speech and the loudest shout. –Normally between (30 and 115 dB SPL) –Tends to be greatest for people with a near normal Fo. –Trained signers may have greater dynamic range.

Speech Acoustics11 AmplitudeVariables continued Voice Range Profile –AKA VRP, phonetogram or FoSPL profile. –Subject sustains a vowel at different Fos, and increases/decreases voice amplitude. –Insert page 59.

Speech Acoustics12 AmplitudeVariables continued Voice Range Profile continued –VRP can be used to get an overall picture of amplitude and frequency. –Can be used to… Determine normal vocal function Monitor treatment for vocal disorder

Speech Acoustics13 Voice Disorders Subjective measures –Perceptual Scales Objective measures –Amplitude –Frequency Use in monitoring progress of treatment Objective measures are more sensitive to changes.

Speech Acoustics14 Neurological Disorders Examples include Parkinson’s Disease, amyotrophic lateral sclerosis (ALS), MS, strokes, brain tumors, TBI, etc. Objective measures can be used to track course of disease or treatment.

Speech Acoustics15 Summary