Even some people with a normal audiogram have listening difficulties (LiD) in daily life. We use multiple auditory tests to differentiate between peripheral and central auditory system problems. It is thought that extended high frequencies audiometry might be useful for the differential diagnosis of LiD. LiD is suspected if no problems are detected in the peripheral auditory system. Recent studies indicated the involvement of poor attention in LiD. People with LiD spend a lot of time in a mindless state or wandering of the mind; as a result, they have difficulty in showing selective attention to important information or adequate divided attention to some stimuli. Using a currently used auditory processing test, it was revealed that there are people who have LiD but pass the auditory processing test, and also people who have no LiD but show poor performance in the auditory test. It is desirable to conduct studies in the future to develop a new auditory processing test to clarify the symptoms and mechanism of LiD.

　 Auditory processing disorder (APD)/listening difficulty (LiD) refers to a condition in which central auditory information processing is impaired despite normal auditory thresholds. Therefore, they have difficulty in hearing in noisy environments and when there are multiple voices. They have hearing and comprehension problems in school or social life, which interfere with communication, learning, and work. For diagnosis, auditory processing tests (APT) are performed after ruling out hearing loss. APT includes the binaural separation test, rapid speech listening test, gap detection threshold test, speech perception in noise, binaural alternate listening test and so on. In Japan, APD/LiD is diagnosed if the SD on more than one item on the APT is under -2SD. Checklists for auditory processing and questionnaires for hearing difficulty are also used to evaluate auditory scenes and the degree of hearing difficulty in them. If the scores are under the standard values, a patient is diagnosed as having subjective APD/LiD. Methods of intervention and support for people with APD/LiD include voice input adjustment, environmental adjustment, device-based information reinforcement, and training. Each method has a bottom-up approach to improve LiD and top-down approach to make it easier to infer the content. It is necessary to analyze the problems and select effective intervention and support for each individual patient.

　 Herein, we discuss the causative pathology of listening difficulties in the presence of clinically normal audiograms, as well as the possible problems with the current diagnosis of this condition. It has been pointed out that cognitive problems, such as impaired attention, may often be involved in this pathology underlie listening difficulties in the presence of a normal audiogram?, and so-called auditory processing tests are considered as being useful for the diagnosis. However, several issues still need to be resolved, as follows: 1) even auditory processing tests may not reveal obvious abnormalities in cases where this pathology is strongly suspected based on other clinical data; 2) the diagnostic significance of auditory processing tests is limited when a subclinical peripheral pathology is suspected to coexist; 3) there are no objective indicators to evaluate the quality and degree (severity) of listening difficulties in these patients. It is desirable to develop and establish better evaluation methods and/or test conditions that will enable a better understanding of this pathology listening difficulties in the presence of a normal audiogram, and improve the quality of diagnosis.

　 Sound therapy using hearing aids has recently been performed for patients with chronic tinnitus also manifesting hearing loss. The aim of this study was to report the effectiveness of our sound therapy with appropriate hearing aid fitting and auditory rehabilitation, called the “Utsunomiya method,” in patients with chronic tinnitus. A total of 95 patients with chronic tinnitus with a pre-treatment Tinnitus Handicap Inventory (THI) score of at least 18 who had received hearing aids were included in this study. The average pre-treatment THI score was 55±24, with a significant decrease to 22±23 at 3 months after treatment, and a minimum of 14±18 by a year. The THI score reduction rate was 75%, and 92% of all cases showed a THI score decrease of 20 or more or a drop of the score to below 16. There was no significant difference in the percent decrease of the THI score between the bilateral and unilateral tinnitus groups. Patients with a left-right difference in hearing of 20dBHL or more tended to have a higher percent reduction of the THI score as compared to those with a difference in hearing of less than 20dBHL. The results of this study suggest that acoustic therapy with hearing aids is an effective treatment for chronic tinnitus patients with hearing loss.

　 The long-term average speech spectrum (LTASS) of the Japanese language was calculated from digital records of free conversations of 10 female adults. Furthermore, to calculate the band importance factor (BIF), we measured the word discrimination score using audiometric frequency band-filtered monosyllabic sounds in 20 adults with normal hearing. From these results, we drew constructed a Japanese count-the-dots audiogram (CDA). Then, we measured the average hearing threshold (4 division method), aided threshold, and maximum word intelligibility score when wearing the hearing aid in 14 hearing aid wearers. Finally, we calculated the speech AI (Articulation Index) and the number of audible dots using the CDA counted from their aided thresholds. Our results revealed that the number of CDA dots was very strongly correlated (R²=0.7831) with the maximum speech intelligibility score. Thus, counting the dots on the Japanese CDA appears to be a clinically valid tool to evaluate the effect of amplification.