Speech Intelligibility Measurements in Tinnitus Patients with and without Hearing Loss

The aim of the study was to determine the effect of hearing loss on speech intelligibility in tinnitus patients. Two new Polish tests for speech intelligibility measurements (the Polish Sentence Test-PST and the Polish Digit Triplet Test-PDTT) were used in the investigation. Tinnitus patients (56 persons) with bilateral sensorineural hearing loss and 28 tinnitus patients with normal hearing thresholds participated in the study. For tinnitus patients with hearing loss, two slopes of the audiograms for higher frequencies were chosen. The speech reception threshold (SRT) for sentence test (SRTs) and for triplet test (SRTT) were determined. Results showed that for tinnitus patients (without hearing loss), the mean SRTs = -4.2 dB and was higher by -1.9 dB than that for normal hearing subjects (control group). For the triplet test, the mean SRTT = -8.1, and was by -1.3 dB higher than SRTT for the control group. This meant that the PST reflected a greater tinnitus influence on the speech intelligibility than the purr. The mean SRTs values for tinnitus patients with sloping audiogram up to 15 dB/oct were within the range from -3.2 to -0.7 dB, while for the larger slopes the mean SRTs values changed from -2.2 dB to 0.48 dB.