Chapter 17, Problem 52PE

A crude approximation at voice production is to consider the breathing passages and mouth to be a resonating tube closed at one end. (See Figure 17.30.) (a) What is the fundamental frequency if the tube is 0.240-m long, by taking air temperature to be 37.0°C? (b) What would this frequency become it the person replaced the air with helium? Assume the same temperature dependence for helium as for air.

Figure 17.30 The throat and mouth form an air column closed at one end that resonates in response to vibrations in the voice box. The spectrum of overtones and their intensities vary with mouth shaping and tongue position to form different sounds. The voice box can be replaced with a mechanical vibrator, and understandable speech is still possible. Variations in basic shapes make different voices recognizable.