To examine the changes in perceived tinnitus sound qualities following internet-based cognitive behavioral therapy (ICBT) for tinnitus. This study was embedded within several clinical trials evaluating the efficacy of ICBT and used a quasi-experimental design (N = 152). Participants completed a series of online questionnaires, including measures of tinnitus sound qualities (Tinnitus Qualities and Impact Questionnaire; TQIQ), tinnitus severity (Tinnitus Functional Index; TFI), anxiety (Generalized Anxiety Disorder-7; GAD-7), depression (Patient Health Questionnaire-9; PHQ-9), insomnia (Insomnia Severity Index; ISI), and health-related quality of life (EQ-5D-5L Visual Analog Scale; VAS). Data were analyzed using a range of parametric and non-parametric statistics, and Cohen's effect sizes were reported. There were no significant differences between the intervention and control groups in sociodemographic and clinical variables at baseline except for anxiety and depression symptoms, which were higher in the intervention group. A statistically significant reduction in tinnitus severity, anxiety, depression, and insomnia was noted post-intervention, with small-to-moderate effect sizes. Statistically significant improvements were also noted for the TQIQ (overall and all subscales) following ICBT compared to the no-intervention group ( ≤ 0.028), all with small-to-large effect sizes, except for the loud sounds subscale and for participants with a TQIQ < 38 at baseline, or "mild" perceived qualities of tinnitus ( ≥ 0.136). A significantly greater proportion of participants in the intervention group had minimum clinically important differences (38%) on the TQIQ compared to the no-intervention group (9%). ICBT can lead to changes in the perceived qualities of tinnitus sound in addition to reducing tinnitus severity and other aspects, such as anxiety, depression, and insomnia. While these findings are preliminary, they highlight that tinnitus distress and perception may be related. However, the study has several limitations including a lack of audiological variables and objective measures. For this reason, the study results must be viewed with caution and must be treated as preliminary.