The impairment of speech perception in noise following pure tone hearing recovery in patients with sudden sensorineural hearing loss

Abstract

To explore whether patients with unilateral idiopathic sudden sensorineural hearing loss (uISSNHL) have normal speech in noise (SIN) perception under different masking conditions after complete recovery of pure tone audiometry. Eight completely recovered uISSNHL patients were enrolled in ISSNHL group, while 8 normal-hearing adults matched with age, gender, and education experience were selected as the control group. Each group was tested SIN under four masking conditions, including noise and speech maskings with and without spatial separation cues. For both ISSNHL and control groups a two-way ANOVA showed a statistically significant effect of masking type (p = 0.007 vs p = 0.012). A significant effect of perceived spatial separation (p < 0.001 vs p < 0.001). A significant interaction between masking type and perceived spatial separation was found (p < 0.001 vs p < 0.001). A paired sample T-test showed that the SIN perception of the control group was statistically significant lower than that of ISSNHL patients only under speech masking without spatial separation cues (p = 0.011). There were still abnormalities in the auditory center shortly after complete recovery in the ISSNHL group (within 2 weeks). However, the auditory periphery and higher-level ability to use spatial cues was normal.

Figure 1

Participants’ SIN perception threshold μ when targets were perceived from left to the threshold when targets were perceived from right.

Figure 2

Group mean percent of correct as a function of signal-to-noise ratio (SNR) in noise masking condition (left panel) and speech masking condition (right panel).

Figure 3

SIN perception threshold under each condition. The error bars represent the standard error of the mean (SEM).

Figure 4

The spatial release from masking of two groups under noise masking and speech masking. The error bars represent the standard error of the mean (SEM).