There is an incoming call on the mobile phone, but there is no sound prompt. Why?

This situation is generally divided into several types:

1, the phone is mute and can't be heard. —— Solution: Set vibration or ring.

2, harassing the phone, hanging up without a sound. -Solution: Ignore.

3. The signal is disturbed or the signal is not good. Solution: move to a place with good signal.

Ringtone type

1, intermediate bell

MIDI is a language. Just as computers can only understand 0 and 1, midi is a common language between electronic musical instruments and related equipment, and it is a multimedia data form of smf (standard midi).

2、SPMIDI

It's similar to midi ringtone, but it adds some control information to make it suitable for mobile phones.

3.MMF ringtone /SMAF

SMAF is a multimedia data format developed by Yamaha, and MMF ringtone is a file in this format. SMAFdeguige is defined as a format that can play multimedia documents on portable terminals. Compared with similar SMF (standard MIDI document), SMAF document has the advantages of small volume and strong expressive force. SMAF is mainly used to make mobile phone ringtones. However, as an extended specification of SMAF, it can also be used to display text and graphics. In this way, SMAF provides a space with strong expressiveness and feasibility when making multimedia tracks on the mobile phone terminal.

4、RTTTL

RTTTL format is a standard ringtone format, which has been supported by many mobile phones.

5.WAV ringtone

The standard sound file format has "cd sound quality", but it takes up too much storage space compared with other compressed format files.

6.WMA ringtone

The file format of Windows Media Audio (wma) only needs the encoding rate of 64kbps, which can achieve the sound quality of cd. Compared with wav, the space occupied by the same content is reduced by half.

7.AMR ringtone

Nokia's commercial naming of ringtones in WB-AMR format (AWB) has been selected by 3GPP (3rd generation partnership project) as the broadband language decoding standard for GSM and 3GWCDMA applications. AMR is a voice standard for mobile communication system proposed by European Communication Standardization Committee. MMS also adopts this format as the sound standard.

8, pigsty

There is a Microsoft compiled sound format.

9、IMY

This is a ringtone specially designed for EMS, which was proposed by Ericsson in 2000 and accepted as a standard by 3GPP in June of 20001year. I-Melody ringtones mark tones based on text, and IrDA is responsible for its standardization. Ericsson and Sony Ericsson, which support EMS, mostly adopt i-Melody ringtone format.

10, PMD ringtone (CMX format)

Cmx is a technology used in cdma network standard. It allows PMD files to contain text, pictures, animations and sounds. All these elements are integrated into a relatively small file, which can be transferred between handheld devices. A PMD file contains audio and/or video. BREW2.0 can play PMD files with mixed audio and video, while BREW 1.0 and 1. 1 can only play audio files. Playing PMD files on devices requires OEM support.

1 1, mp3 ringtone

Speaking of mp3 ringtones, first of all, it should be mentioned that MPEG is short for Moving Picture Expert Group. This expert group was established in 1988, and is responsible for establishing the video and audio compression standard for optical discs. MPEG audio file refers to the sound part of MPEG standard, namely MPEG audio layer. MPEG files can be divided into three layers according to the different compression quality and coding complexity (mpegaudiololayer 1/2/3 corresponding to mp 1, mp2 and mp3 respectively. The compression rate of MPEG audio coding is very high. The compression rates of mp 1 and mp2 are 4: 1 and 6: 1-8: 1, while the compression rate of mp3 is as high as1-12. Therefore, at present, the music format mp3 on the Internet is the most common. Through a coding algorithm called "sensory coding technology", mp3 bits are used to reduce the sound distortion: when coding, the frequency spectrum of audio files is analyzed, then the noise frequency is filtered by a filter, and then the remaining bits are dispersed and quantized, and finally an mp3 file with high compression ratio is formed, so that the compressed file can achieve a sound effect closer to the original sound source when playing back. Although it is a kind of lossy compression, its biggest advantage is that it has a high compression ratio with minimal sound distortion.

12, m4r ringtone

M4r is an audio format of iPhone ringtone. The Iphone system comes with 25 kinds of ringtones, including Malimba, ringtone (spring sound), vibrato, pinball, piano repetition, barking, guitar plucking and so on. The format is m4r, which allows users to add custom ringtones.

Source: Baidu Encyclopedia: Ringtones