Synæsthesia is an incarnation of Frontline Assembly members Bill Leeb and Rhys Fulber. It is one of several including: Pro-tech , Equinox , Intermix, and Delerium in addition to FLA. Synæsthesia is probably the most strictly ambient of all these groups. The music consists almost entirely of long minimalist instrumental stretches. Its closest comparison to other Leeb/Fulber projects would likely be Spiritual Archives or Stone Tower by Delerium. Stylistically this incarnation appears to be a continuation of the Delerium sound from these albums, as Delerium itself became more dancy and incorporated vocals. The monks chanting in catacombs remained with Delerium, but most that group's ambience seems to have moved into Synæsthesia.

Due to contractual entanglements Leeb and Fulber were not originally able to admit they were behind the music. The first two albums list them as producers and credit the music to one R. Deckard, alluding to the main character from Blade Runner. By their third album Leeb was credited with the music. Fulber, who had recently left to pursue solo projects, was credited with programming.

Albums include:

• Desideratum (1995)
• Embody (1995)
• Ephemeral (1997)
• Collection (2001)