Institute for Transport StudiesFaculty of Environment

Comparing performance on a number of auditory memory tasks: Implications for how auditory information is perceived in vehicles

Nick HerbertNatasha MeratNick ThyerSarah Isherwood

• Humans have a limited capacity to perform tasks

• Dual-task studies applied in the driving domain

• Auditory & cognitive distractions

Background

• Cognitively engaging auditory tasks affect driving (e.g. Strayer & Johnston, 2001; Strayer et al. 2003)

• E.g. cognitive tunneling, visual tunneling, reduction in visual span (Victor et al. 2005; Wood et al., 2006; Reimer, 2009)

• Greater task difficulty Greater effect

Background

• Cognitive aspect of task is usually manipulated

• Examples: • more difficult sums

(Harbluk et al., 2007)

• storage of more information in memory (Jamson & Merat, 2005)

• manipulation of information e.g. word generation (Strayer & Johnston, 2001)

Background

Background

• It’s difficult hearing sound in the car:• In-car acoustics (rear seat passengers,

noisy cabin, little visual information etc.)

• Sensory loss

• So does the difficulty in perceiving the sound source have an effect on task performance?

• Ease of language understanding model (Ronnberg et al., 2008)

Background

• Do small differences in task difficulty result in significant differences in task performance?

• Young, normally hearing participants (n = 25)

• Asked to perform single tasks

• Accuracy & reaction time

Study 1

• 0-back (Mehler et al., 2009): 3 , 2 , 8 , 1 , 6 , 6 , 9 , 1 , 3 ,

• 2-back: 3 , 2 , 8 , 1 , 6 , 6 , 9 , , 3 , 7

• Digit continuous memory task (Jamson & Merat, 2005; Engström, 2005): 1 , 5 , 1 , 3 , , 4 , , , 3 , 9

• Tone continuous memory task

• Paced auditory serial addition task (Rizzo et al., 2004; Uc et al., 2006): 1 , 4 , 3 , 2 , 1

Tasks

Study 1

0-back Digit CMT Tone CMT PASAT

Digit CMT .083

Tone CMT .004 .013

PASAT < .001 < .001 .657

2-back < .001 < .001 .020 .002

Study 1

0-back Digit CMT Tone CMT PASAT

Digit CMT < .001

Tone CMT < .001 < .001

PASAT < .001 .001 .657

2-back < .001 < .001 .002 .443

Study 2

• Three tasks carried forward:• 0-back

• Digit continuous memory task

• Paced auditory serial addition task

• Applied two levels of hearing loss simulation to the stimuli (Moore & Glasberg, 1993; Baer & Moore, 1993)

• Expected that explicit processing required, thus task performance would decrease

Background

• Young, normally hearing participants (n = 27)

• Asked to perform single tasks

• Accuracy & reaction time

Study 2

Study 2

0-back Digit CMT PASAT

No hearing loss vs mild hearing loss .232 .357 .896

No hearing loss vs moderate hearing loss < .001 .026 < .001

Mild hearing loss vs moderate hearing loss < .001 .043 < .001

Study 2

0-back Digit CMT PASAT

No hearing loss vs mild hearing loss .614 .313 .631

No hearing loss vs moderate hearing loss < .001 < .001 < .001

Mild hearing loss vs moderate hearing loss .002 .010 < .001

Summary

• Small differences in task type chosen can still have an effect on performance

• Need for standardisation/research into this

• Moderate hearing loss has the capacity to make auditory tasks significantly more challenging

• This may have a knock-on effect on driving

Next steps

• Questionnaire study

• Effect of hearing loss on useful field of view

• Dual-task driving simulator study with simulated hearing loss

• Detection response task

Questions?

hc06nch@leeds.ac.uk