Dealing with communication challenges in relationships can be a complex and frustrating experience, especially when it comes to processing delays in sound. In your situation, it seems that your partner has a unique way of processing auditory information that leads to misunderstandings and a breakdown in communication. While it can be easy to focus on changing the other person’s behavior, it's often more effective to adjust our own responses, as you've discovered.

First, it’s important to understand the nature of auditory processing. Individuals who experience delays in processing sounds may not have hearing loss; instead, their brains take longer to interpret the sounds they hear. This can lead to moments where they respond with confusion or need additional time to comprehend what was said. According to the American Speech-Language-Hearing Association, auditory processing disorders can manifest in various ways, including difficulty in following verbal instructions or responding promptly to spoken information.

In your case, the repeated “what?” followed by an eventual understanding suggests that your partner is still processing the information, even if it may seem immediate to you. This can create a cycle of frustration, especially when you feel that your words are not being acknowledged or understood in real-time. It’s understandable that this would lead to irritation, especially after a decade of marriage.

However, your realization that you can change your own reaction rather than trying to change his behavior is a significant breakthrough. Here are some strategies that can help further:

• Practice Patience: When he responds with “what,” try to take a deep breath and give him those three seconds of silence. This can help create a more relaxed environment and reduce tension.
• Use Visual Cues: Sometimes, supporting verbal communication with non-verbal cues, such as gestures or facial expressions, can help him process the information more quickly.
• Clarify and Confirm: After you’ve waited and he has responded, you can ask him to confirm what he understood. For example, “Just to make sure we’re on the same page, did you get that I want to go for a walk?” This can reinforce understanding.
• Set Aside Time for Communication: Establishing specific times for discussions where distractions are minimized can help improve overall communication. This could be during dinner or while taking a walk together.

It's also worth mentioning that communication in relationships is a two-way street. Just as you are adjusting your reaction, it might be beneficial to share your feelings with him about how his responses affect you. Open dialogue can foster an environment of understanding and support.

In your journey to improve communication, remember that it’s completely normal to feel frustrated. Acknowledging these feelings is part of the process. It’s commendable that you’ve found a solution that works for both of you. As you continue to navigate this aspect of your relationship, consider exploring resources on effective communication strategies, such as The Four Horsemen of the Apocalypse by Dr. John Gottman, which discusses common communication pitfalls in relationships and how to overcome them.

Ultimately, it’s about building a stronger connection and understanding each other’s unique ways of processing information. Your proactive approach is a testament to your commitment to a healthy and supportive relationship.