Using more realistic speech material to enhance ecological validity in the Everyday Conversational Danish Sentence...

Area of Science:

• Audiology
• Speech perception research
• Psychoacoustics

Background:

• Traditional audiological tests lack real-world ecological validity.
• Verbatim sentence tests do not reflect natural speech communication.
• A need exists for speech materials that better represent everyday listening conditions.

Purpose of the Study:

• To develop and validate a new, ecologically valid Danish speech material for audiological testing.
• To compare the psychometric properties of the new material with the traditional Danish Sentence Test (DAST).
• To investigate the impact of vocal effort and noise on speech intelligibility.

Main Methods:

• Developed the Everyday Conversational Danish Sentence Test (ECDST) using dialogue recordings.
• Presented 400 ECDST sentences to 40 normal-hearing participants in spectrally matched noise.
• Tested across five signal-to-noise ratios (SNRs) from -10 to 0 dB.

Main Results:

• The ECDST demonstrated a speech reception threshold (SRT) of -5.3 dB SNR and a slope of 12.1%/dB.
• These results were comparable to the DAST corpus (SRT: -5.17 dB SNR; slope: 11.5%/dB).
• Vocal effort significantly influenced intelligibility, with effects varying by SNR.

Conclusions:

• The ECDST offers comparable psychometric properties to traditional tests while enhancing ecological validity.
• This new speech material can improve the assessment of real-world speech understanding.
• Intelligibility-normalized ECDST lists are ready for future clinical implementation.