Monitoring Resonance Changes in the Mature Female Voice with Acoustic Software
Objective
Menopause, loss of elastic and collagenous fibres and loss of smoothness at the edge of the vocal folds, may cause changes in vocal timbre and vocal fold vibration. It is important to monitor these changes over time in order to use effective teaching methods to mitigate these changes. Perceptual acoustic changes can be perceived with the aid of acoustic software. The author has explored the possibility of scoring these changes in order create a robust and objective way of monitoring the voice.
Method
A group of singers and a group of non-singers were asked to vocalise on a vowel chain of 5 Italian vowels. These were recorded in Voce Vista Pro. The power spectrum, the spectrograph and the vibrato track were used to assess the components of the voice which were considered to be attributes of good tone and resonance, resulting from a well-produced vibration from the voice source producing many strong harmonics. The software allowed for assessment and scoring of the following acoustic features:
• Mode of phonation
• Vocal intensity
• The position and strength of the formants
• Evidence of a singer’s formant cluster.
• Does the position of the first and second formant of the [i] and [_] vowels indicate a convergent vocal tract.
• Is there consistent vibrancy across the formants on all five vowels.
• Is there evidence of non-harmonic noise in the spectrogram.

Results
The professional singers all had the highest scores. All results were extremely variable with no obvious pattern of improvement or deterioration over time. The scores tallied with the subjective judgement of experts indicating that this method of scoring resonance was robust and had validity.
Conclusions
Technical proficiency is a factor in maintaining good tone. Age-related changes do not cause deterioration of tone. This system has the potential to become an excellent method for taking baseline measurements of vocal tone, similar to the GRBAS system and can monitor vocal change over time.
Rebecca Moseley-Morgan
PhD, MA(mus), BA(hons), ARCM(hons), FISM