Posted by: Footler PJ24 JUL 2013
Presbyphonia is a term used to describe changes in voice quality with age. The voice may sound quieter or more breathy, it may become hoarse or it may have a reduced pitch range.
The changes occur as the larynx muscles atrophy with ageing and because the neuromuscular junction between the nerve that signals the vocal muscle to work and the muscle itself becomes degraded. The vocal folds do not close properly during vibration.
Patients are advised to drink plenty of fluids, stop smoking and avoid dry atmospheres. Surgery and medical treatment can help but may not be advisable in elderly patients. Speech therapy may be offered and some new evidence that vocal training could affect the physiology as well as the strength of vocal muscles comes from researchers working with what they call “singing” rats.
Rats employ similar neuromuscular vocal mechanisms to humans, although special recording equipment is needed to lower their ultrasonic calls for humans to hear. Groups of old and young male rats were trained to increase their number of vocalisations by offering them a female rat but removing her when the male showed an interest.
The males responded by increased vocalisation and were rewarded with food. Training continued for eight weeks and then the intensity of the vocalisations and the condition of the neuromuscular junctions were compared with those of untrained control groups.
The researchers found that, although the trained old and young rats had similar average vocal intensities, the untrained older rats had lower average intensities than both the trained rats and the untrained young rats.
They also found that, while the neuromuscular junction on the muscle disperses or breaks apart with age, it was not as dispersed in the older rats that received training. This suggests that vocal training can not only reduce the effects of age on the vocal muscles but may improve voices that have already degraded.