Development of the child's voice: premutation, mutation.

Area of Science:

• Pediatric Voice Science
• Developmental Phonetics
• Speech-Language Pathology

Background:

• Understanding typical vocal development in children is crucial for identifying voice disorders.
• Previous research has provided general timelines for vocal changes during childhood.

Purpose of the Study:

• To quantitatively assess vocal capabilities in healthy children aged 4-12 years.
• To identify age- and sex-specific changes in voice range profiles (VRPs).

Main Methods:

• Utilized an automatic Voice Range Profile (VRP) measurement system.
• Measured fundamental frequency (F0) and sound pressure level (SPL) for speaking, shouting, and singing voices.
• Analyzed data from 180 children (10 boys and 10 girls per age group from 4-12 years).

Main Results:

• Vocal capabilities generally increase with age but not uniformly.
• A significant lowering of habitual pitch and speaking pitch range occurs around ages 7-9.
• Temporary reductions in speaking and singing vocal intensity (ability to speak softly) are observed at ages 7-8.
• Maximum speech intensity decreases around ages 7-9.
• Shouting voice pitch and intensity decrease from age 10 onwards.
• Identified a premutation stage in girls aged 7-8, mirroring changes seen in boys a year later.
• The onset of voice mutation is observed between ages 10-11.

Conclusions:

• Childhood vocal development is characterized by distinct phases of change in pitch and intensity.
• Vocal changes occur earlier in girls than in boys, particularly during the premutation phase.
• These findings refine our understanding of typical vocal maturation and provide normative data for clinical assessment.