This is known as the "Barrel Effect" and may be caused by several factors including a shallow placement of the hearing device in your ear, or inadequate low frequency setting. You may try one or more of the following to resolve:
1. Try re-positioning the hearing device in your ear. Pulling the ear flap or pinna back often helps with proper placement.
2. Try a smaller Comfort Tip size, which could result in deeper placement and less barrel effect. Beware as this may increase the chance of feedback due to inadequate sealing in your ear.
3. Try to reduce (or sometimes increase) the low frequency amplification of the hearing device by running the HD Setting Application and adjusting the level of "Loud Male Voice". Make sure you save all your new settings before you exit the application and replace the battery module.