Want your voice to to convey more warmth? Just smile:

There’s only one thing you need to do in order to project more warmth in your voice: smile. Smiling affects how we speak to such an extent that listeners in one study could identify sixteen different kinds of smiles based on sound alone. This is why it’s worth smiling even when on the phone.

• Check your breathing. Make sure you’re breathing deeply into your belly and inhale and exhale through your nose rather than your mouth. Breathing through your mouth can make you sound breathless and anxious.

• Speak slowly. Visualize the contrast between a nervous, squeaky teenager speaking at high speed and the slow, emphatic tone of a judge delivering a verdict.

• Pause. People who broadcast confidence often pause while speaking. They will pause for a second or two between sentences or even in the middle of a sentence. This conveys the feeling that they’re so confident in their power, they trust that people won’t interrupt.