Alien Race that communicates via pheromones - how to stat it?

[whswhs]

Looking at the RaW, I see that Cannot Speak is -15, and Mute is -25. But both of those are mundane physical traits; that is, they apply to normal human beings who lack pheromones, chameleon skins, electrical pulses, telepathy, and so on, and thus are limited by not having speech.

For comparison, Subsonic Speech is 10 points if you can also speak at normal frequencies, but 0 points if you can only speak at subsonic frequencies. The 0 points applies even though you speak more slowly and can't convey as much information. So it appears that (a) being unable to speak at audible frequencies is not a limitation if you can speak at other frequencies, (b) being able to speak at other frequencies is not an advantage if you can't speak at audible frequencies, and (c) the differences in the details of how things work are usually treated as a wash.

So let's consider some examples:

You can communicate by chemical signals. I think that's worth 0 points if that's your only way of communicating, but 10 points if you can also speak. The 10 points includes the ability to detect a wider range of chemical signals than a human being can and/or to detect them at a greater distance. By itself this is worth 5 points, just as Subsonic Hearing is worth 5 points (less than the 15 points for Discriminatory Smell; it wouldn't give you the full benefits, but it might give you the lesser bonuses for Sensitive if you were close to the subject). In any case I'd say "chemical signals" rather than "pheromones," as the latter is a technical term and describes things other than cognitively based communication.

You can communicate via a cable jack. This is worth 5 points if you can also speak, but I think 0 points if you can only use a cable jack.

You can communicate by changing skin color in patterns. I think that the ability to see those patterns is free as a part of human level vision. I might charge 5 points, to represent the difference between only being able to see and also being able to generate patterns, and include one level of Chameleon; or I might charge 10 points, with 5 points for the basic chromophores and 5 point for a level of Chameleon. But if you can't talk, I'd either drop the cost to 0 points (including a level of Chameleon for free) or drop it to 5 points (just for the level of Chameleon).