Age-Related Changes in Voice Emotion Recognition by Postlingually Deafened Listeners With Cochlear Implants

Abstract

Objectives: Identification of emotional prosody in speech declines with age in normally hearing (NH) adults. Cochlear implant (CI) users have deficits in the perception of prosody, but the effects of age on vocal emotion recognition by adult postlingually deaf CI users are not known. The objective of the present study was to examine age-related changes in CI users' and NH listeners' emotion recognition.

Design: Participants included 18 CI users (29.6 to 74.5 years) and 43 NH adults (25.8 to 74.8 years). Participants listened to emotion-neutral sentences spoken by a male and female talker in five emotions (happy, sad, scared, angry, neutral). NH adults heard them in four conditions: unprocessed (full spectrum) speech, 16-channel, 8-channel, and 4-channel noise-band vocoded speech. The adult CI users only listened to unprocessed (full spectrum) speech. Sensitivity (d') to emotions and Reaction Times were obtained using a single-interval, five-alternative, forced-choice paradigm.

Results: For NH participants, results indicated age-related declines in Accuracy and d', and age-related increases in Reaction Time in all conditions. Results indicated an overall deficit, as well as age-related declines in overall d' for CI users, but Reaction Times were elevated compared with NH listeners and did not show age-related changes. Analysis of Accuracy scores (hit rates) were generally consistent with d' data.

Conclusions: Both CI users and NH listeners showed age-related deficits in emotion identification. The CI users' overall deficit in emotion perception, and their slower response times, suggest impaired social communication which may in turn impact overall well-being, particularly so for older CI users, as lower vocal emotion recognition scores have been associated with poorer subjective quality of life in CI patients.

Figure 1.

Pure-tone air-conduction thresholds (dB HL) averaged across participants from 250–8000 Hz by younger (< 60 years, open circles) and older (> 60 years, filled circles) normally hearing participants. Standard deviations are shown as error bars for each frequency.

Figure 2.

Comparison of d’ (top) and reaction times (bottom) obtained in normally hearing and CI participants. Data are separated by Female (left panel) and Male Talker (right panel). Lines indicate linear regressions. (Open circles/solid line: normally hearing; filled circles/dashed line: CI participants.

Figure 3.

Effects Age on d’ (top) and reaction times (bottom) with the four degrees of spectral degradation (shapes) by normally hearing participants. Data are separated by Female (left panel) and Male Talker (right panel). Lines indicate linear regressions. (Circles/solid line - Full Spectrum, squares/dashed line – 16 Channel, diamonds/dotted line– 8 Channel, triangles/dot dashed line – 4 channel)

Figure 4.

4A. Two-way interaction between Age and Degree of Spectral Degradation (shapes) in d’ data. Lines indicate linear regressions. (Circles/solid line - Full Spectrum, squares/dashed line – 16 Channel, diamonds/dotted line– 8 Channel, triangles/dot dashed line – 4 channel) 4B. Boxplots showing two-way interaction between Talker and Degree of Spectral Degradation in d’ data (filled = Female; open = Male).

Figure 5.

Boxplots showing two-way interaction between Talker and Degree of Spectral Degradation in reaction time data (filled = Female; open = Male).

Figure 6.

Comparison of reaction time data (averaged across the two talkers) obtained in normally hearing and CI participants plotted against Age. Data are separated into Correct (left panel) and Incorrect trials (right panel). Lines indicate linear regressions. (Open circles/solid line: normally hearing; filled circles/dashed line: CI participants.