The relationship between the intensity levels and speech production fluency in the delayed auditory feedback test in normally hearing listeners

Background and Aim: Sometimes people with functional hearing loss are referred to audiology clinics. The delayed auditory feedback (DAF) is a test which assesses functional hearing loss qualitatively. This study aimed to quantify DAF and accordingly use it in more precise way.Methods: Fifteen normally hearing students participated in this experiment. Each person’s voice was presented to his or her ear once without and another time with fixed time delay when he or she was reading simple texts. The delayed voices were presented in different intensity levels. Stuttering, unusual lengthy, and non-fluent utterances indicated the perception and hearing of the delayed voices.Results: The length of the utterances increased and the fluency of the utterances decreased significantly for delayed compared to non-delay condition and for different intensity levels.Conclusion: These results showed that the levels of intensity of the delayed voices might influence the perception of the delay.