Let's discuss fan types. Part 1, Sound/Echo type.

1. So, what is this type all about?

Sound/Echo-type is largely proposed as a type for buffing up sound-based Pokémon, many of which have incredibly low BSTs and sound-type moves which have incredibly low base powers.

The primary driving force behind this proposal is the fact that almost all sound-based Pokémon are either Normal-type or single-typed. Introduction of a Sound/Echo-type is supposed to help reduction of the base of Normal-type as a hodge-podge of all elements that don't fit into an established type, and grant a new STAB for powerless Pokémon, similar to how Fairy type born out of Normal-type.

2. Where does the name come from?

The name Sound-type comes from the "sound-based moves", which comes from the ability Soundproof's description.

The name Echo-type instead comes from Echo TCG deck, a TCG deck that focused on Normal-type Pokémon. Word Echo is also used in a later English TCG deck, Enchanted Echo.

3.Does this type have a in-game source?

The difference between Sound-type with other proposed types is that there is a specific category of sound-based moves, as mentioned above. The abilities of these moves are;

1. They bypass Substitute(as of Generation VI)
2. Many of them hit multiple opponents(as of Generation III)
3. They are avoided by Soundproof(as of Generation III).

In addition, since Generation I, there has been several sound-based moves(such as Sing) and Pokémon(such as Jigglypuff).

Sound-type also has a legendary dedicated to sound-based moves in the form of Meloetta.

4.What would be ideas behind such type?

One of the primary issue behind Sound-type becoming canonical is the issue of physical moves. Sound-based moves by nature are status based and special moves. Any physical move in relation to these must have physical contents, which might be based on the concept of Rhythm.

Other concepts here to be used are the concepts used in Sound based moves:

1. Singing
2. Roaring
3. Screams
4. Buzzing
5. Supersonic
6. Whistling

5.What would be the type interactions of such a type?

The highest connections of such a type would be based on the nature of sound, specifically its speed in different environments. Due to sound's association with normal, it is reasonable to expect that it will be blocked by Rock and Steel. Because sound moves faster in areas where there is more matter for sound to move from, it is reasonable that it will be resisted by Air, hit neutral to Water and hit super effectively to Ground.

But because sound is not a physical matter, its resistances and weaknesses are harder to imagine. Something based on the health of the vocal cords would most certainly work, however, whatever that may be.

6.What would be distrubition of such a type?

Most of the existing sound-based Pokémon are early to mid-route Pokémon, so it is reasonable to expect that such a type would work as an early route elemental type, in the vein of Water, Grass, Electric and Dark.

It is likely that most powerful Pokémon in this type would be based on Pokémon with high type variety and interesting abilities, not that the type itself is a high level type.

7.Future comments:

Because many sound based Pokémon such as Bug-types and Noibat-line cannot have a new type, it is possible that sound based moves will have more special properties with special items and abilities.