For testing audio code with headphones on...

ProtectYourEars.h

#pragma once

#include <JuceHeader.h>

/**
  Silences the buffer if bad or loud values are detected in the output buffer.
  Use this during debugging to avoid blowing out your eardrums on headphones.
  If the output value is out of the range [-1, +1] it will be hard clipped.
 */
inline void protectYourEars(float *buffer, int sampleCount)
{
  if (buffer == nullptr) { return; }
  bool firstWarning = true;
  for (int i = 0; i < sampleCount; ++i) {
    float x = buffer[i];
    bool silence = false;
    if (std::isnan(x)) {
      DBG("!!! WARNING: nan detected in audio buffer, silencing !!!");
      silence = true;
    } else if (std::isinf(x)) {
      DBG("!!! WARNING: inf detected in audio buffer, silencing !!!");
      silence = true;
    } else if (x < -2.0f || x > 2.0f) {  // screaming feedback
      DBG("!!! WARNING: sample out of range, silencing !!!");
      silence = true;
    } else if (x < -1.0f) {
      if (firstWarning) {
        DBG("!!! WARNING: sample out of range, clamping !!!");
        firstWarning = false;
      }
      buffer[i] = -1.0f;
    } else if (x > 1.0f) {
      if (firstWarning) {
        DBG("!!! WARNING: sample out of range, clamping !!!");
        firstWarning = false;
      }
      buffer[i] = 1.0f;
    }
    if (silence) {
      memset(buffer, 0, sampleCount * sizeof(float));
      return;
    }
  }
}

You could in theory get an oscillating wave between -1.999 and +1.999 and it would still be very loud, even after clipping. Most of the time, though, when things go wrong it's because of values exploding and going to infinity. That's what this protects against.

@hollance interesting, thanks!