some test code using Rust's cpal library which reads audio data from the microphone

try_cpal.rs

fn catch_error(err: StreamError) {
    println!("found error {:?}",err);
}

fn get_audio() {
    let mut num_samples = Arc::new(AtomicUsize::new(0));
    let num_samples2 = num_samples.clone();
    let catch_data = move |data: &[f32], _info: &InputCallbackInfo| {
        num_samples.fetch_add(data.len(), Ordering::Relaxed);
    };

    let host = cpal::default_host();
    if let Some(device) = host.default_input_device() {
	if let Ok(config) = device.default_input_config() {
            let custom_config = cpal::StreamConfig {
		channels : 2,
		sample_rate: cpal::SampleRate(44100),
                buffer_size: cpal::BufferSize::Default
            };
            if let Ok(stream) = device.build_input_stream (&custom_config,
                                                           catch_data,
                                                           catch_error) {
                stream.play();
                std::thread::sleep(std::time::Duration::from_secs(20));
                stream.pause();
                println!("number of samples {:?}",num_samples2);
            }
        }
    }
}