void setGain(int sourceId, double gain) {
		AL10.alSourcef(sourceId, AL10.AL_GAIN, (float) gain);		
		int error = AL10.alGetError();
		if (error != AL10.AL_NO_ERROR) {
			this.logger.logError(LOGGING_SOURCE, "unable to set gain of open al source, error: " + error);
		}		
	}