The aim of this work was to measure subjective speech intelligibility in an enclosure with a long reverberation time and comparison of these results with objective parameters. Impulse Responses (IRs) were first determined with a dummy head in different measurement points of the enclosure. The following objective parameters were calculated with Dirac 4.1 software: Reverberation Time (RT), Early Decay Time (EDT), weighted Clarity (C50) and Speech Transmission Index (STI). For the chosen measurement points, a convolution of the IRs with the Polish Sentence Test (PST) and logatome tests was made. PST was presented at a background of a babble noise and speech reception threshold - SRT (i.e. SNR yielding 50% speech intelligibility) for those points were evaluated. A relationship of the sentence and logatome recognition vs. STI was determined. It was found that the final SRT data are well correlated with speech transmission index (STI), and can be expressed by a psychometric function. The difference between SRT determined in condition without reverberation and in reverberation conditions appeared to be a good measure of the effect of reverberation on speech intelligibility in a room. In addition, speech intelligibility, with and without use of the sound amplification system installed in the enclosure, was compared.

The aim of the study was to determine the signal-to-noise ratio (SNR) for the Speech Reception Threshold (SRT) for young persons with normal hearing. The following three tests available for Polish language were used: the New Articulation Lists (NAL-93) version of 2011, the Polish Sentence Test (PST) and the Polish Sentence Matrix Test (PSMT). When using PST and PSMT the masking signal was babble noise made of the language material contained in the test. For NAL-93 the masking signal was speech noise. The speech reception threshold (SRT) was found to be (−6:8 ± 1.1), (−4:8 ± 1.6), (−3:5 ± 1.8) and (−3:4 ± 2.0) dB SNR for PST, PSMT, NAL-93 (constant stimuli method) and NAL-93 (short method), respectively. The values of SRT depend on semantic redundancy of the language material. Differences in SRT were statistically non-significant only for NAL-93 (constant stimuli method) and NAL-93 (short method). Moreover, it was shown that the time needed for presentation of a single word list (NAL-93, short method) or single sentence list (PST, PSMT) was comparable and equal to 2–3 minutes. The most uniform SRT values were obtained for PST. The PSMT was the least demanding for the listener, experimenter and equipment.

Objective: Self-report questionnaire is informative to assess general hearing disability. The aims of this study were to investigate the reliability of Turkish version of spatial hearing questionnaire (SHQ) and to analyze the validity of the SHQ by the correlation with speech, spatial, and qualities of hearing questionnaire (SSQ) and Turkish matrix sentence test (TMST).
Methods: The first part of the study was the psychometric properties of the SHQ with 192 participants (137 with normal hearing, 55 with hearing loss). In the second and main part of the study, we applied two questionnaires (SHQ and SSQ) and TMST to people other than those included in the first part ofthe study (88 participants with bilateral sensorineural hearing loss). We compared the results of these two questionnaires and the TMST with the speech discrimination (SD) scores.
Results: Turkish spatial hearing questionnaire’s internal consistency was 0.94 and 0.97 for individuals with normal hearing and for individuals with hearing loss, respectively. Moderate, positive, statistically significant correlation was observed between the SHQ and SSQ (r = 0:606, p = 0:001 in individuals with hearing loss who do not wear any hearing aid, and r = 0:627, p = 0:001 in hearing aid users), and SHQ and SD (r = 0:561, p = 0:032 in hearing aid users). According to TMST, moderate, positive, statistically significant correlation was found between SSQ and adaptive TMST in individuals with hearing loss who do not wear any hearing aid (r = 0:330, p = 0:033 for S0N90 and r = 0:364, p = 0:018 for S0N270).
Conclusions: Turkish SHQ is a valid and reliable questionnaire for assessing hearing functions. SHQ, SSQ, and TMST are clinically beneficial measuring tools in planning the process of hearing rehabilitation and follow-up.