The development and validation of the speech quality instrument

Area of Science:

• Audiology
• Speech Science
• Psychophysics

Background:

• Standardized tools are lacking to quantify perceived speech quality, despite its importance in hearing evaluation.
• Existing speech perception tests do not adequately capture the subjective experience of speech quality.

Purpose of the Study:

• To develop and validate a tool for measuring the quality of heard speech.
• To create a reliable instrument for assessing subjective speech characteristics.

Main Methods:

• A prospective instrument validation study involving 35 normal-hearing adults.
• Participants rated 44 speech clips (original and manipulated) on 18 characteristics using a visual analog scale (VAS).
• Statistical analyses, including skewed distribution analysis and factor analysis, were used for instrument refinement.

Main Results:

• The Speech Quality Instrument (SQI) was refined to nine speech clips representing key qualities.
• High internal consistency (Cronbach's alpha 0.95 and 0.82) and test-retest reliability (ICC 0.76) were demonstrated.
• Original female speech clips received the highest ratings (8.8), while non-speech manipulations received the lowest (2.1).

Conclusions:

• The Speech Quality Instrument (SQI) is a concise and valid tool for assessing speech quality.
• SQI can serve as an indicator of hearing performance.
• This instrument may be valuable for evaluating cochlear implant recipients experiencing subjective speech quality issues.