Auditory capacity of the better-hearing ear in asymmetric hearing loss

Abstract

Purpose: Our aim was to investigate the course of the hearing capacity of the better-hearing ear in single-sided deafness (SSD) and asymmetric hearing loss (AHL) over time, in a multicenter study.

Methods: We included 2086 pure-tone audiograms from 323 patients with SSD and AHL from four hospitals and 156 private practice otorhinolaryngologists. We collected: age, gender, etiology, duration of deafness, treatment with CI, number and monosyllabic speech recognition, numerical rating scale (NRS) of tinnitus intensity, and the tinnitus questionnaire according to Goebel and Hiller. We compared the pure tone audiogram of the better-hearing ear in patients with SSD with age- and gender-controlled hearing thresholds from ISO 7029:2017.

Results: First, individuals with SSD showed a significantly higher hearing threshold from 0.125 to 8 kHz in the better-hearing ear compared to the ISO 7029:2017. The duration of deafness of the poorer-hearing ear showed no relationship with the hearing threshold of the better-hearing ear. The hearing threshold was significantly higher in typically bilaterally presenting etiologies (chronic otitis media, otosclerosis, and congenital hearing loss), except for Menière's disease. Second, subjects that developed AHL did so in 5.19 ± 5.91 years and showed significant reduction in monosyllabic word and number recognition.

Conclusions: Individuals with SSD show significantly poorer hearing in the better-hearing ear than individuals with NH from the ISO 7029:2017. In clinical practice, we should, therefore, inform our SSD patients that their disease is accompanied by a reduced hearing capacity on the contralateral side, especially in certain etiologies.

Keywords: AHL; Asymmetric hearing loss; SSD; Single-sided deafness; Unilateral hearing loss.

Fig. 1

Comparison of air-conducted pure-tone thresholds from 0.125 kHz to 8 kHz between subjects with SSD (grey) and age- and gender-controlled hearing thresholds from ISO 7029:2017 (blue). SSD subjects with single-sided deafness; level of significance: *** - p < 0.001; ** - p < 0.01; * p < 0.05

Fig. 2

Correlation of air-conducted pure-tone thresholds average difference (AC PTA4 difference = PTA4 better-hearing ear—PTA4 from ISO 7029:2017) with duration of deafness in years in subjects with SSD. The AC PTA4 difference is the difference between the individual AC PTA4 of the better-hearing ear of subjects with SSD and age- and gender-controlled hearing thresholds from ISO 7029:2017. SSD subjects with single-sided deafness

Fig. 3

A Comparison of the average difference in air-conducted pure-tone thresholds (AC PTA4 difference = PTA4 better-hearing ear—PTA4 from ISO 7029:2017) in relation to etiology in subjects with SSD. The AC PTA4 difference is the difference between the individual AC PTA4 of the better-hearing ear of subjects with SSD and age- and gender-controlled hearing thresholds from ISO 7029:2017. B Comparison of the average difference in air–bone gap pure-tone thresholds (AC PTA4 air–bone gap = PTA4 better-hearing ear—PTA4 from ISO 7029:2017) in relation to etiology in subjects with SSD. SSD subjects with single-sided deafness, TA pure-tone measurements, SHL sudden hearing loss, Schwannoma vestibularis schwannoma, chronic OM chronic otitis media; level of significance: *** - p < 0.001; - ** p < 0.01; * - p < 0.05

Fig. 4

Comparison of air-conducted pure-tone thresholds from 0.125 kHz to 8 kHz between non-CI users with SSD (white) and A preoperative pure-tone audiograms of CI users with SSD (grey) and B postoperative pure-tone audiograms of CI users with SSD (grey). SSD subjects with single-sided deafness; level of significance: *** - p < 0.001; ** - p < 0.01; * - p < 0.05

Fig. 5

Correlation of air-conducted pure-tone thresholds average (AC PTA4) with duration of deafness in years in subjects that went from SSD to AHL. AHL asymmetric hearing loss, SSD subjects with single-sided deafness