A Review of the Effect of Age and Speech Stimulus on Nasalance Scores in Healthy Participants

Instrumental assessments can provide numerical values in nasality assessment. One of these instruments is the nasometer (Kay Elemetrics¡ Lincoln Park¡ NJ¡ USA). The nasometer measures the oral and nasal acoustic energy during speech and the resultant signal is expressed as a nasalance score. The aim of the current review was to study the impact of age and speech stimulus on nasalance score through a systematic review of studies on nasalance.
The ASHA publication¡ PubMed¡ ScienceDirect¡ Google Scholar¡ Cochrane¡ Wiley¡ ProQuest¡ IranDoc¡ and SID databases were searched using the keywords “nasalance”¡ “nasometer”¡ “normative nasalance score”¡ and “instrumental assessment of resonance disorders” for related articles published between 1990 and 2016.
Based on the inclusion and exclusion criteria¡ 38 of the 67 published documents were selected to be reviewed. The review showed that different studies had obtained different results regarding the effect of age and speech stimulus on nasalance scores.
As¡ in addition to age and speech stimulus¡ many factors (like language¡ accent¡ and gender) affect nasalance scores¡ a meta-analysis study seems to be necessary on this topic.