Elderly listeners' identification of Japanese long vowel pair `obasan' and `obaasan' using pitch and duration

Abstract

Japanese has long and short vowel distinction. While duration is the primary cue for listeners, pitch is being used as the secondary cue when duration becomes ambiguous. Duration however is affected by phonetic environment and therefore pitch cues may be more important in daily conversations. At the same time, ageing is known to affect speech recognition, in particular, pitch contour discrimination, such as tones. The current study compared a group of 15 young listeners with 14 elderly listeners using the words 'obasan (aunt)' and 'obaasan (grandmother),' manipulated in six steps duration-wise and pitch-wise. We found elderly listeners to use pitch more than the young listeners at the duration extremes, suggesting a generational effect on acceptability in accents (or lack of). At the same time, we observed half the elderly listeners to be less sensitive to pitch when duration becomes unreliable, depending on their fundamental frequency difference limens. The more sensitive elderly listeners, who performed similarly to the younger participants, significantly differed in their perception results from the less sensitive elderly listeners. This suggests that pitch deficits are present in half of the near-normal hearing elderly group, contributing to their inability to use pitch cues as well as their younger counterpart.

Pitch and duration as auditory cues to identify Japanese long vowels for Japanese learners

“…The following procedure and stimuli manipulation are identical to the test design detailed in [7]. The minimal pair ''obaasan'' (grandmother) and ''obasan'' (aunt) were chosen as stimuli for this study as they differ in the length of /a/ and both words are expected to be taught at a similarly early stage for Japanese learners.…”

“…The audio files were also normalised in terms of their intensity to avoid effect of loudness on the perception of the words. The same stimuli were used in [7].…”

“…She found that while the distinction was particularly hard for learners with native languages that do not have pitch differences, the perceptual boundary for advanced learners and learners with a tonal native language such as Mandarin became similar to that of a native Japanese speaker. In a different study, Hui found some differences between elderly and young native Japanese listeners on their use of pitch cues to distinguish between vowel quantities [7], especially when the elderly listeners have difficulties in pure tone discrimination.…”

Effect of frequency discrimination abilities on music and speech perception: A summary of four short studies

“…Only the pitch results for when duration (6 stimuli) is ambiguous will be reported in the current paper. This study has been published as part of a bigger study with the duration and pitch manipulation [6].…”

“…The first study to be discussed is part of a bigger study on the perception of the long Japanese vowel word pair ''obasan (aunt)'' and ''obaasan (grandmother)'' [6]. The current summary will focus on the use of pitch to distinguish between the pair when duration becomes ambiguous.…”