The first is voiced sound. Let me make an analogy. In Japanese, the pronunciation of ただ and だ is slightly different from that of "da da" in Chinese. As an unvoiced sound, た is not as strong as the airflow exhaled by ta, and だ is trembling in the throat from beginning to end. For example, pronounce だ: first, and then stick your tongue on the upper gum at the same time, with both sides of your tongue close to the upper jaw. Then, in order to pronounce the following だ, you have to pronounce だ. These things can only be understood. Similarly, by replacing ぁ with ぇぉ and other vowels, you can pronounce で and ど similar to the above actions.

Then the vowels. Actually, I think this is much easier to read than voiced sound. If you really want an official explanation, it is the consonants "K", "S" and "T" plus the semi-consonant "Y" and the vowels "A", "E" and "O" and then add up to "Kyu".

Personally, I will teach you a quick way to distinguish between unvoiced and voiced sounds, such as reading ta da and Tadatada quickly every day ... like this, so are other unvoiced and voiced sounds.