Kids with cochlear implants have poorer control over pitch

A new Canadian study suggests that kids with cochlear implants in both ears may face difficulty controlling the loudness and pitch of their voices.

However, according to the report published in the January issue of Archives of Otolaryngology-Head & Neck Surgery, one of the JAMA/Archives journals, these measures improve with time.

Theresa Holler and colleagues at The Hospital for Sick Children, University of Toronto, Ontario, Canada, examined 27 children aged 3 to 15 who had had cochlear implants in both ears.

These children were told to voice the vowel "a" for three seconds at a comfortable pitch and volume. Three repetitions of this voice testing were averaged, assessed digitally and compared with acoustic results of children who had an implant in one ear and also with standards for hearing children.

Those who had implants in both ears showed poorer control over the pitch and loudness of their voice than those with normal hearing. Long-term control of pitch became better as kids used their hearing aids, and therefore were exposed to hearing for more time.

The authors give a backgrounder in their report saying: "Cochlear implants provide the perception of sound through the conversion of sound stimuli into electrical impulses, which are received by the cochlear nerve and processed by the central auditory system.

They continue: "Although cochlear implants do not restore sound perception as experienced by an individual with normal hearing, the implant provides the user with auditory feedback in the domains of timing, intensity and frequency of sound. These auditory feedback cues may be critical for the user to monitor his or her speech production and to make purposeful moment-to-moment adjustments in voicing."

The authors add: "To our knowledge, this is the first study to objectively evaluate acoustic voice outcomes in children with bilateral cochlear implants and to report the influence of overall time in sound on acoustic parameters.

"Targeted speech therapies that assist children using cochlear implants in monitoring and modifying the pitch and loudness of their voice would be useful in this setting," they conclude. "Future work is planned to develop and evaluate therapeutic tools that will specifically address these areas in implant recipients, with the objective of minimizing or eliminating these voice abnormalities."