NOTAM has started a project where the goal is to make a collection of impulse responses from various acoustic spaces in the Oslo region. An acoustic impulse response is a recording of how a certain sonic environment resounds an audio signal when played back from a speaker into the space. The recording registers the space’s reverb characteristics, and can be analyzed by a program which in turn uses the data to create a reverb filter. Such a reverb filter is called convolution reverb, and recreates a realistic version of the reverb characteristics of the space where the impulse response was recorded. In other words, it is possible to send any given audio file through a convolution reverb in order to make it sound like it was recorded in a desired sonic environment.

Cato Langnes and Notto J W Thelle are responsible for the project. So far, we have captured impulse responses from the following locations:

• Nordberg church
• Vestre Aker church
• Jar church
• Grønland church
• Ny Musikk’s exhibition area
• Cafeteatret
• Lindemansalen, Norwegian Music Academy
• Levinsalen, Norwegian Music Academy
• Parkteatret
• Studio at Henie Onstad Kunstsenter

The long-term goal is to record several more impulse responses and offer convolution reverbs which can be used with the plugin Altiverb from Audio Ease. Audio Ease already offers the room characteristics of Uranienborg kirke, Margaretakyrkan and Emmanuel Vigelad’s mausoluem.

We will also make the impulse responses available for download directly from our website.