Vocal characteristics of 5-year-old children: proposed normative values based on a French-speaking population†

Voice Parameters in Children With Cochlear Implants: A Systematic Review and Meta-Analysis

INTRODUCTION

An intact auditory system is essential for the development and maintenance of voice quality and speech prosody. On the contrary hearing loss affects the adjustments and appropriate use of organs involved in speech and voice production. Spectro-acoustic voice parameters have been evaluated in Cochlear Implant (CI) users, and the authors of previous systematic reviews on the topic concluded that fundamental frequency (F0) seemed preliminarily the most reliable parameter to evaluate voice alterations in adult CI users. The main aim of this systematic review and meta-analysis was to clarify the vocal parameters and prosodic alterations of speech in pediatric CI users.

MATERIALS AND METHODS

The protocol of the systematic review was registered on the PROSPERO database, International prospective register of systematic reviews. We conducted a search of the English literature published in the period between January 1, 2005 and April 1, 2022 on the Pubmed and Scopus databases. A meta-analysis was conducted to compare the values of voice acoustic parameters in CI users and non-hearing-impaired controls. The analysis was conducted using the standardized mean difference as the outcome measure. A random-effects model was fitted to the data.

RESULTS

A total of 1334 articles were initially evaluated using title and abstract screening. After applying inclusion/exclusion criteria, 20 articles were considered suitable for this review. The age of the cases ranged between 25 and 132 months at examination. The most studied parameters were F0, Jitter, Shimmer and Harmonics-to-Noise Ratio (HNR); other parameters were seldom reported. A total of 11 studies were included in the meta-analysis of F0, with the majority of estimates being positive (75%); the estimated average standardized mean difference based on the random-effects model was 0.3033 (95% CI: 0.0605 to 0.5462; P = 0.0144). For Jitter (0.2229; 95% CI: -0.1862 to 0.7986; P = 0.2229) and shimmer (0.2540; 95% CI: -0.1404 to 0.6485; P = 0.2068) there was a trend toward positive values without reaching statistical significance.

DISCUSSION AND CONCLUSIONS

This meta-analysis confirmed that higher F0 values have been observed in the pediatric population of CI users compared to age-matched normal hearing volunteers, whereas the parameters of voice noise were not significantly different between cases and controls. Prosodic aspects of language need further investigations. In longitudinal contexts, prolonged auditory experience with CI has brought voice parameters closer to the norm. Following the available evidence, we stress the utility of inclusion of vocal acoustic analysis in the clinical evaluation and follow-up of CI patients to optimize the rehabilitation process of pediatric patients with hearing loss.

Acoustic voice and spectrographic measures in children with the phonological process of devoicing

INTRODUCTION

Children with speech sound disorders (SSDs) who present the devoicing of plosive and/or fricative sounds may have difficulties with glottal respiratory control.

OBJECTIVE

To analyze acoustic vocal measures, spectrographic aspects and the risk of dysphonia among children with devoicing SDDs and compare the results with those of other groups of children.

METHODS

Twenty-five boys aged between six and 12 years participated. They were divided into four groups: the SSD-devoicing (PPDG), dysphonia (DG), SSDs other than devoicing (PPOG) and control groups (CG). The vocal tasks were recorded, and perceptual-auditory and acoustic voice analyses were performed. The children's parents answered questions about voice-related aspects (to determine a dysphonia risk score). All data were compared among the groups.

RESULTS

Due to the sample size, an effect size analysis was considered, and the results showed possible differences between the PPDG and the other groups in measures of fundamental frequency (F0), jitter, shimmer, harmonic-to-noise ratio, maximum frequency of harmonic definition and dysphonia risk score.

CONCLUSIONS

The PPDG showed a high F0 and abnormal jitter and shimmer values. Although the voices of the children in this group had more harmonics than noise, the maximum frequency for defining the harmonics was very restricted. The PPDG had the lowest dysphonia risk score among all of the groups. Variations in F0, jitter and shimmer may indicate difficulties with controlling vocal adjustments, which appear to be hyperfunctional and not to impact vocal projection or voicing.