Measuring age-related differences in phonetic gradiency with the visual analogue scale and eye tracking.

Older adults showed more categorical patterns of phonetic perception than younger adults in the visual analogue scale (VAS) task.

• The study compared a younger adult sample (ages 18–25) to an older adult sample (age 50+).
• Age-related differences in VAS ratings persisted even after controlling for hearing loss and speech-in-noise perception.
• The VAS task elicited ratings for a set of four phonetic continua.
• The VAS task was described as particularly sensitive to both age-related factors and differences in language skill.

Eye tracking measures also provided evidence of more categorical patterns of phonetic perception among older adults.

• Study 2 used a two-alternative forced choice (2AFC) task with eye tracking.
• The eye tracking paradigm provided both binary response data and fine-grained fixation data for the same phonetic continua as Study 1.
• Evidence of more categorical perception among older adults was found in the eye tracking measures, though the effect was described as less pronounced than in the VAS task.

The VAS task was found to be particularly sensitive to age-related factors and individual differences in language skill.

• Several assessments examined how language skill, hearing acuity, and speech-in-noise perception were associated with individual differences in phonetic categorization.
• The VAS task elicited more gradient versus categorical response patterns compared to the binary 2AFC task.
• Language skill was associated with individual differences in phonetic categorization as measured by the VAS.

The study examined multiple potential contributors to age-related differences in phonetic perception, including hearing acuity and speech-in-noise perception.

• Assessments of language skill, hearing acuity, and speech-in-noise perception were conducted to examine their association with phonetic categorization.
• Age-related differences in VAS performance persisted after statistically controlling for hearing loss and speech-in-noise perception.
• This suggests that age-related differences in phonetic gradiency are not solely attributable to peripheral hearing loss or degraded speech-in-noise processing.

The study employed two different measurement approaches—VAS and eye tracking within a 2AFC task—to capture phonetic sensitivity across the adult lifespan.

• Study 1 used a visual analogue scale (VAS) task to elicit continuous ratings.
• Study 2 used a two-alternative forced choice task with eye tracking, yielding both binary responses and fixation data.
• Both studies used the same set of four phonetic continua, allowing for methodological comparison.
• The two methods differed in their sensitivity to age-related and language-skill-related differences in phonetic perception.